Сделал много изменений, сами все посмотрите.

src/main/java/ru/neroduckale/nerodays/DiscordWebhook.java

@@ -13,6 +13,8 @@ import java.util.List;
 import java.util.Map;
 import java.util.Set;
 
+import static ru.neroduckale.nerodays.nerodays.LOGGER;
+
 /**
  * Class used to execute Discord Webhooks with low effort
  */

src/main/java/ru/neroduckale/nerodays/Events.java

@@ -1,7 +1,5 @@
 package ru.neroduckale.nerodays;
 
-import com.google.gson.JsonObject;
-import net.minecraft.network.chat.Component;
 import net.minecraft.server.level.ServerPlayer;
 import net.minecraft.world.damagesource.DamageSource;
 import net.minecraft.world.entity.LivingEntity;
@@ -9,6 +7,7 @@ import net.minecraftforge.event.ServerChatEvent;
 import net.minecraftforge.event.TickEvent;
 import net.minecraftforge.event.entity.living.LivingDeathEvent;
 import net.minecraftforge.event.entity.player.AdvancementEvent;
+import net.minecraftforge.event.entity.player.PlayerEvent;
 import net.minecraftforge.eventbus.api.SubscribeEvent;
 
 import java.awt.*;
@@ -39,35 +38,44 @@ public class Events {
 
 
     @SubscribeEvent
-    public void NewDay(TickEvent.LevelTickEvent worldTickEvent) throws IOException {
+    public void NewDay(TickEvent.LevelTickEvent worldTickEvent) {
         if (worldTickEvent.level.getDayTime() % 24000 == 0) {
             var a = worldTickEvent.level.getDayTime() / 24000;
             if (days != a) {
                 days = (int) a;
             } else {return;}
             var m = "Новый день! День: " + a;
-            LOGGER.error(m);
+            DiscordWebhook.EmbedObject embed = new DiscordWebhook.EmbedObject()
-            serverwebhook.setContent(m);
+                .setTitle(m)
+                .setColor(Color.white);
+            serverwebhook.addEmbed(embed);
+            try {
                 serverwebhook.execute();
-            serverwebhook.setContent("");
+            } catch (IOException exception) {
+                LOGGER.error(exception.getMessage());
+            }
         }
     }
 
 
     @SubscribeEvent
-    public void NewMsg(ServerChatEvent event) throws IOException {
+    public void NewMsg(ServerChatEvent event) {
         var nickname = event.getUsername();
         var message = event.getMessage().getString();
         webhook.setUsername(nickname);
         webhook.setContent(message);
         webhook.setAvatarUrl("https://ely.by/services/skins-renderer?url=http://skinsystem.ely.by/skins/%s&scale=10&renderFace=1".formatted(nickname));
+        try {
             webhook.execute();
+        } catch (IOException exception) {
+            LOGGER.error(exception.getMessage());
+        }
     }
 
 
 
     @SubscribeEvent
-    public void Death(LivingDeathEvent event) throws IOException {
+    public void Death(LivingDeathEvent event) {
 
         if (event.getEntity() instanceof ServerPlayer player) {
             var nickname = player.getDisplayName().getString();
@@ -79,25 +87,79 @@ public class Events {
                     .setTitle(chlen)
                     .setColor(Color.red);
             serverwebhook.addEmbed(embed);
+            try {
                 serverwebhook.execute();
+            } catch (IOException exception) {
+                LOGGER.error(exception.getMessage());
+            }
 
         }
     }
 
 
     @SubscribeEvent
-    public void onNewAchivment(AdvancementEvent.AdvancementEarnEvent event) throws IOException {
+    public void onNewAchievement(AdvancementEvent.AdvancementEarnEvent event) {
+        if (event.getAdvancement().getDisplay() == null) return;
+        String id = event.getAdvancement().getId().getPath().replace("/", ".");
+
+        String description;
+        String title;
+        if (json.get("advancements.%s.description".formatted(id)).getAsString() == null) {
+            description = event.getAdvancement().getDisplay().getDescription().getString();
+        } else {
+            description = json.get("advancements.%s.description".formatted(id)).getAsString();
+        }
+
+        if (json.get("advancements.%s.title".formatted(id)).getAsString() == null) {
+            title = event.getAdvancement().getDisplay().getTitle().getString();
+        } else {
+            title = json.get("advancements.%s.title".formatted(id)).getAsString();
+        }
 
         var nickname = event.getEntity().getDisplayName().getString();
-        var achivka = event.getAdvancement().toString();
         var message = nickname + " получил ачивку!";
         DiscordWebhook.EmbedObject embed = new DiscordWebhook.EmbedObject()
                 .setAuthor(message, "", "https://ely.by/services/skins-renderer?url=http://skinsystem.ely.by/skins/%s&scale=10&renderFace=1".formatted(nickname))
-                .setTitle(achivka)
+                .setTitle(title)
+                .setDescription(description)
+                .setColor(Color.green);
+        serverwebhook.addEmbed(embed);
+        try {
+            serverwebhook.execute();
+        } catch (IOException exception) {
+            LOGGER.error(exception.getMessage());
+        }
+
+    }
+
+
+    @SubscribeEvent
+    public void playerJoin(PlayerEvent.PlayerLoggedInEvent event) {
+        var nickname = event.getEntity().getDisplayName().getString();
+        String message = nickname + " зашел на сервер!";
+        DiscordWebhook.EmbedObject embed = new DiscordWebhook.EmbedObject()
+                .setAuthor(message, "", "https://ely.by/services/skins-renderer?url=http://skinsystem.ely.by/skins/%s&scale=10&renderFace=1".formatted(nickname))
+                .setColor(Color.green);
+        serverwebhook.addEmbed(embed);
+        try {
+            serverwebhook.execute();
+        } catch (IOException exception) {
+            LOGGER.error(exception.getMessage());
+        }
+    }
+    @SubscribeEvent
+    public void playerLeave(PlayerEvent.PlayerLoggedOutEvent event) {
+        var nickname = event.getEntity().getDisplayName().getString();
+        String message = nickname + " вышел с сервера.";
+        DiscordWebhook.EmbedObject embed = new DiscordWebhook.EmbedObject()
+                .setAuthor(message, "", "https://ely.by/services/skins-renderer?url=http://skinsystem.ely.by/skins/%s&scale=10&renderFace=1".formatted(nickname))
                 .setColor(Color.red);
         serverwebhook.addEmbed(embed);
-        serverwebhook.execute(); //НЕ ПРОВЕРЯЛ
+        try {
-    }
+            serverwebhook.execute();
-
+        } catch (IOException exception) {
+            LOGGER.error(exception.getMessage());
+        }
+    }
 }
 

src/main/java/ru/neroduckale/nerodays/nerodays.java

@@ -1,23 +1,21 @@
 package ru.neroduckale.nerodays;
 
-import com.google.gson.JsonDeserializer;
-import com.google.gson.JsonElement;
 import com.google.gson.JsonObject;
 import com.google.gson.JsonParser;
 import com.mojang.logging.LogUtils;
-import net.minecraft.resources.ResourceLocation;
 import net.minecraftforge.common.MinecraftForge;
+import net.minecraftforge.event.server.ServerStartingEvent;
 import net.minecraftforge.eventbus.api.IEventBus;
 import net.minecraftforge.eventbus.api.SubscribeEvent;
 import net.minecraftforge.fml.common.Mod;
-import net.minecraftforge.event.server.ServerStartingEvent;
 import net.minecraftforge.fml.javafmlmod.FMLJavaModLoadingContext;
 import org.slf4j.Logger;
 
+import java.awt.*;
 import java.io.BufferedReader;
 import java.io.IOException;
 import java.io.InputStreamReader;
-import java.io.UnsupportedEncodingException;
+import java.nio.charset.StandardCharsets;
 
 
 @Mod(nerodays.MODID)
@@ -31,21 +29,21 @@ public class nerodays
     public static JsonObject json;
 
 
-    public nerodays() throws UnsupportedEncodingException {
+    public nerodays() throws IOException {
         IEventBus modEventBus = FMLJavaModLoadingContext.get().getModEventBus();
 
         MinecraftForge.EVENT_BUS.register(this);
         MinecraftForge.EVENT_BUS.register(new Events());
 
-        var readIn = new BufferedReader(new InputStreamReader(getClass().getClassLoader().getResourceAsStream("assets/nerodays/ru_ru.json"), "UTF-8"));
+        var readIn = new BufferedReader(new InputStreamReader(getClass().getClassLoader().getResourceAsStream("assets/nerodays/ru_ru.json"), StandardCharsets.UTF_8));
         json = JsonParser.parseReader(readIn).getAsJsonObject();
     }
 
     @SubscribeEvent
     public void onServerStarting(ServerStartingEvent event) throws IOException {
-        serverwebhook.setContent("Сервер запущен!");
+        serverwebhook.addEmbed(new DiscordWebhook.EmbedObject().setTitle("Сервер включен!").setColor(Color.white));
         serverwebhook.execute();
-        serverwebhook.setContent("");
+
     }