Login Packet Sender

[Dummmye]

I'm trying to add this to my minecraft server on 1.20.4 with .16.14 fabric and it will not start the console keeps outputting this

java.lang.NoClassDefFoundError: net/fabricmc/fabric/api/networking/v1/LoginPacketSender
at modpackChecker.NetworkHandler.registerVersionHandler(NetworkHandler.java:66) ~[ModpackChecker-0.1.2+1.20.x.jar:?]
at modpackChecker.NetworkHandler.register(NetworkHandler.java:20) ~[ModpackChecker-0.1.2+1.20.x.jar:?]
at modpackChecker.ModpackChecker.onServerStarting(ModpackChecker.java:39) ~[ModpackChecker-0.1.2+1.20.x.jar:?]
at net.fabricmc.fabric.api.event.lifecycle.v1.ServerLifecycleEvents.lambda$static$0(ServerLifecycleEvents.java:38) ~[fabric-lifecycle-events-v1-2.3.1+a67ffb5d4f-7cf332d584f520a8.jar:?]
at net.minecraft.server.MinecraftServer.handler$zjn000$fabric-lifecycle-events-v1$beforeSetupServer(MinecraftServer.java:2909) ~[server-intermediary.jar:?]
at net.minecraft.server.MinecraftServer.method_29741(MinecraftServer.java:650) ~[server-intermediary.jar:?]
at net.minecraft.server.MinecraftServer.method_29739(MinecraftServer.java:270) ~[server-intermediary.jar:?]
at java.lang.Thread.run(Thread.java:833) ~[?:?]
Caused by: java.lang.ClassNotFoundException: net.fabricmc.fabric.api.networking.v1.LoginPacketSender
at jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:641) ~[?:?]
at java.lang.ClassLoader.loadClass(ClassLoader.java:520) ~[?:?]
at net.fabricmc.loader.impl.launch.knot.KnotClassDelegate.loadClass(KnotClassDelegate.java:226) ~[fabric-loader-0.16.14.jar:?]
at net.fabricmc.loader.impl.launch.knot.KnotClassLoader.loadClass(KnotClassLoader.java:119) ~[fabric-loader-0.16.14.jar:?]
at java.lang.ClassLoader.loadClass(ClassLoader.java:520) ~[?:?]
... 8 more

I'm not good with code so I'm unsure what this may mean