Warning: Trying to access array offset on value of type null in C:\server\xampp\htdocs\hng\apieng\api_getcmd_post.php on line 53

Fatal error: Uncaught ValueError: mysqli::query(): Argument #1 ($query) cannot be empty in C:\server\xampp\htdocs\hng\apieng\api_getcmd_post.php:55 Stack trace: #0 C:\server\xampp\htdocs\hng\apieng\api_getcmd_post.php(55): mysqli->query('') #1 C:\server\xampp\htdocs\hng\apieng\api_getcmd_post.php(66): rows->select() #2 {main} thrown in C:\server\xampp\htdocs\hng\apieng\api_getcmd_post.php on line 55