How to setup keybinds 1.15

[Saksham4106]

I can't seem to find any help on keybinds for 1.15 I have registered my keybinds and I know I have to send packets to server because I want to make change in Item properties
I also saw a tutorial on how to send packets (MCJTY's )but the problem is what should I do in the packets if I want to make keybinds. what should be in the packets.. what info what to send I have sincerely no clue. i don't have any experience in keybinds and packets so please bare me if my doubt is stupid

[Saksham4106]

  public boolean handle(Supplier<NetworkEvent.Context> ctx) {
	        ctx.get().enqueueWork(() -> {
	            ServerWorld spawnWorld = ctx.get().getSender().world.getServer().getWorld(type);
	            EntityType<?> entityType = ForgeRegistries.ENTITIES.getValue(id);
	            if (entityType == null) {
	                throw new IllegalStateException("This cannot happen! Unknown id '" + id.toString() + "'!");
	            }
	            entityType.spawn(spawnWorld, null, null, pos, SpawnReason.SPAWN_EGG, true, true);
	        });
	        return true;
	    }

this is the handle method I saw in the tutorial how should I change the item's properties
I want to make a wand that changes the spell on pressing a key so I will have to change the item's state

[Saksham4106]

so the main code I want to do after the key is pressed should be in the handle method