Taging user after command

So if run it like this

function onMessageHandler (target, context, msg, self, userstate) {
if (self) { return; }

const commandName = msg.trim();

if (commandName === ‘!tag’) {
client.action(target, @${userstate.username}, whatever);
console.log(executed command);
}
}

idk why it doesnt show `` in code but its before @ starting one and after whatever ending one

and i get :