Code

client.js

import * as alt from 'alt';
import * as native from 'native';

let view = new alt.WebView('http://resources/authentication/client/html/index.html');
alt.showCursor(true);
view.focus();
alt.toggleGameControls(false);

var loginCamera;

view.on('formLoginUser', (username, password) => {
    alt.emitServer('clientLoginUser', username, password);
});

view.on('formRegisterUser', (username, email, password) => {
    alt.emitServer('clientRegisterUser', username, email, password);
});

alt.on('connectionComplete', () => {
    freezePlayer();
});

alt.onServer('destroyAuth', () => {
    freePlayer();
});

function freezePlayer() {
    native.freezeEntityPosition(alt.Player.local.scriptID, false);

    loginCamera = native.createCam('DEFAULT_SCRIPTED_CAMERA', 1);
    native.setCamCoord(loginCamera, 619.84912109375,1143.0748291015625,353.6922302246094);
    native.setCamRot(loginCamera, -6.675822734832764,0,-55.17519760131836);
    native.setCamFov(loginCamera, 65);
    native.setCamActive(loginCamera, true);
    native.renderScriptCams(true, false, 0, false, false);
    native.setFocusArea(619.84912109375,1143.0748291015625,353.6922302246094, 5, 0.0, 0.0, 0.0);    
    native.setHdArea(619.84912109375,1143.0748291015625,353.6922302246094, 5, 30);
}

function freePlayer() {
    native.clearFocus();
    native.clearHdArea();

    view.destroy();

    native.renderScriptCams(false, false, 0, true, false);
    native.setCamActive(loginCamera, false);
    native.destroyCam(loginCamera, false);

    alt.showCursor(false);
    alt.toggleGameControls(true);
    
    native.freezeEntityPosition(alt.Player.local.scriptID, false);
}

eventFunctions.js

import * as alt from 'alt';
import * as chat from 'chat';

var users = {};

export function playerConnect(player) {
	player.spawn(0, 0, 72, 0);
	player.dimension = 1;
}

export function playerConnectComplete(player) {
	alt.emitClient(player, 'toggleChat', false);

	users[player.name] = null;

	player.user = function () {
		return users[player.name];
	}
}

export function playerDisconnect(player) {
	
}

export function authSuccess(player, user) {
	player.dimension = 0;

	alt.emitClient(player, 'toggleChat', true);
	alt.emitClient(player, 'destroyAuth');

	users[player.name] = user;

	alt.log(`[DEBUG] Added user object to ${player.name}: ${player.user().username} (ID: ${player.user().id})`);
}

events.js

import * as alt from 'alt';
import * as eventFuncs from './eventFunctions.mjs';

alt.on('playerConnect', eventFuncs.playerConnect);
alt.on('connectionComplete', eventFuncs.playerConnectComplete);

alt.on('playerDisconnect', eventFuncs.playerDisconnect);

alt.on('authSuccess', eventFuncs.authSuccess);