gun doesn't create user in alias check

user-alias-gun.js

    $('#up').on('click', function(e) {
        e.preventDefault();
        let aliasIn = $('#alias').val()
        let passIn = $('#pass').val()
        gun.get("~@" + aliasIn).once(function (uAlias) {
            if (uAlias === undefined) {
                console.log("alias undefined, registering.")
                user.create($('#alias').val(), $('#pass').val(), function (ack) {
                    console.log("create user ack: " + ack)
                    user.auth($('#alias').val(), $('#pass').val());
                });
            } else {
                console.log("Error: User " + alias + " already exists. Cannot register.")
            }
        })
    })