Warning: Unsupported declare 'strict_types' in D:\xampp\htdocs\masterweb_android_api\vendor\kreait\firebase-php\src\Firebase\Http\Responses.php on line 3

Parse error: syntax error, unexpected '$this' (T_VARIABLE) in D:\xampp\htdocs\masterweb_android_api\vendor\kreait\firebase-php\src\Firebase\Http\Responses.php on line 28