conecta() - N�o foi poss�vel conectar ao mysql server

Fatal error: Uncaught TypeError: mysqli_set_charset(): Argument #1 ($mysql) must be of type mysqli, bool given in /home/lopes/domains/comercialopes.com.br/public_html/app/controllers/app_controller.php:14 Stack trace: #0 /home/lopes/domains/comercialopes.com.br/public_html/app/controllers/app_controller.php(14): mysqli_set_charset() #1 /home/lopes/domains/comercialopes.com.br/public_html/vendor/drumon_core/class/app.php(130): include('...') #2 /home/lopes/domains/comercialopes.com.br/public_html/index.php(11): App::run() #3 {main} thrown in /home/lopes/domains/comercialopes.com.br/public_html/app/controllers/app_controller.php on line 14