My Mixin code:

@Mixin(ClientPlayNetworkHandler.class)
public abstract class ClientPlayNetworkHandlerMixin {

    @Shadow public abstract ClientConnection getConnection();

    @Inject(method = "<init>", at = @At("RETURN"))
    private void onInit(CallbackInfo info) {
        System.out.println("ClientPlayNetworkHandler initialized. Connection: " + getConnection());
    }

    @Overwrite
    private void sendResourcePackStatus(ResourcePackStatusC2SPacket.Status packStatus) {
        if (this.getConnection() != null && packStatus != null) {
            this.getConnection().send(new ResourcePackStatusC2SPacket(packStatus));
            System.out.println("test " + packStatus);
        } else {
            System.err.println("Connection is null, cannot send resource pack status.");
        }
    }
}

fabric.mod.json:

{
    "schemaVersion": 1,
    "id": "yesidownloadedyourresourcepack",
    "version": "${version}",
    "name": "YesIDownloadedYourResourcepack",
    "description": "now you wont be kicked from server because you dont want to download his faithful resourcepack",
    "authors": [
        "TheMixRay"
    ],
    "contact": {
        "homepage": "https://fabricmc.net/",
        "sources": "https://github.com/FabricMC/fabric-example-mod"
    },
    "license": "CC0-1.0",
    "icon": "assets/yesidownloadedyourresourcepack/icon.png",
    "environment": "client",
    "entrypoints": {
        "client": [
            "com.themixray.YesIDownloadedYourResourcepack"
        ]
    },
    "mixins": [
        "yesidownloadedyourresourcepack.mixins.json"
    ],
    "depends": {
        "fabricloader": ">=0.15.7",
        "minecraft": "~1.20.1",
        "java": ">=17",
        "fabric-api": "*"
    },
    "suggests": {
        "another-mod": "*"
    }
}

yesidownloadedyourresourcepack.mixins.json:

{
    "required": true,
    "package": "com.themixray.mixin",
    "compatibilityLevel": "JAVA_17",
    "mixins": [
        "ClientPlayNetworkHandlerMixin"
    ],
    "injectors": {
        "defaultRequire": 1
    }
}

my folders tree

essentially, when I go to the server and reject/accept a resource pack, I should see it in the console, but in the console I only see this error, which hardly relates to my mod:

[20:28:32] [Worker-Main-3/ERROR]: Caught exception in thread Thread[Worker-Main-3,4,main]
java.lang.NullPointerException: Cannot read field "field_3752" because "$$0" is null
    at net.minecraft.class_641.method_44294(class_641.java:157) ~[client-intermediary.jar:?]
    at net.minecraft.class_641.method_44090(class_641.java:170) ~[client-intermediary.jar:?]
    at net.minecraft.class_3846.method_16907(class_3846.java:91) ~[client-intermediary.jar:?]
    at net.minecraft.class_3846.method_16900(class_3846.java:146) ~[client-intermediary.jar:?]
    at net.minecraft.class_3846.run(class_3846.java:102) ~[client-intermediary.jar:?]
    at java.util.concurrent.ForkJoinTask$RunnableExecuteAction.exec(ForkJoinTask.java:1395) ~[?:?]
    at java.util.concurrent.ForkJoinTask.doExec(ForkJoinTask.java:373) ~[?:?]
    at java.util.concurrent.ForkJoinPool$WorkQueue.topLevelExec(ForkJoinPool.java:1182) ~[?:?]
    at java.util.concurrent.ForkJoinPool.scan(ForkJoinPool.java:1655) ~[?:?]
    at java.util.concurrent.ForkJoinPool.runWorker(ForkJoinPool.java:1622) ~[?:?]
    at java.util.concurrent.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:165) ~[?:?]

I tried to remove the client folder and write all my code in main, but it doesn’t make sense