Warning: Trying to access array offset on value of type null in /home/schooltr/public_html/header_template.php on line 8

Fatal error: Uncaught mysqli_sql_exception: Access denied for user 'schooltr'@'localhost' to database 'schooltr_' in /home/schooltr/public_html/header_template.php:15 Stack trace: #0 /home/schooltr/public_html/header_template.php(15): mysqli_select_db(Object(mysqli), 'schooltr_') #1 /home/schooltr/public_html/index.php(8): include('/home/schooltr/...') #2 {main} thrown in /home/schooltr/public_html/header_template.php on line 15