PHP_SMART_HOME_V3/app/plugins/Spotify.php

<?php
class Spotify extends VirtualDeviceManager {
	private $token = "";
	private $client_id = '76840e2199e34dcd903d19877bd726dd'; // Your client id
	private $redirect_uri = 'https://dev.steelants.cz/vasek/home-update/plugins/spotify/callback'; // Your redirect uri

	public function oAuth(){
		$client_secret = 'CLIENT_SECRET'; // Your secret
		$scopes = 'user-read-private user-read-email';

		header('Location: https://accounts.spotify.com/authorize?client_id='. $this->client_id . '&response_type=token&redirect_uri='.urlencode($this->redirect_uri).'&scope=user-read-playback-state');
	}

	private function setToken($token){
		$this->token = $token;
	}

	public function callback(){
		var_dump($_REQUEST);
		(new SettingsManager)->create('spotify_token', $token);
	}

	public function autorize(){

		$client_secret = '0f94ed2c0bd64bf791ea13b7e6310ba3';

		$ch = curl_init();
		curl_setopt($ch, CURLOPT_URL,            'https://accounts.spotify.com/api/token' );
		curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1 );
		curl_setopt($ch, CURLOPT_POST,           1 );
		curl_setopt($ch, CURLOPT_POSTFIELDS,     'grant_type=client_credentials&scope=user-read-playback-state' );
		curl_setopt($ch, CURLOPT_HTTPHEADER,     array('Authorization: Basic '.base64_encode($this->client_id.':'.$client_secret)));

		$result=curl_exec($ch);

		$this->setToken(json_decode($result, true)['access_token']);
		echo $result;
	}

	private function getPlayerData(){
		$ch = curl_init();
		curl_setopt($ch, CURLOPT_URL,            'https://api.spotify.com/v1/me/player' );
		curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1 );
		curl_setopt($ch, CURLOPT_HTTPHEADER,     array('Authorization: Bearer ' . (new SettingsManager)->getByName('spotify_token')['value']));

		$result=curl_exec($ch);
		echo $result;
	}

	function fetch($url = 'true')
	{
		$this->autorize();
		$this->getPlayerData();
	}
}