Fatal error: Uncaught Error: Call to undefined function mysql_connect() in /volume1/studiowinter/wp-includes/wp-db.php on line 1645

Error: Call to undefined function mysql_connect() in /volume1/studiowinter/wp-includes/wp-db.php on line 1645

Call Stack:
    0.0001     401320   1. {main}() /volume1/studiowinter/index.php:0
    0.0002     403024   2. require('/volume1/studiowinter/wp-blog-header.php') /volume1/studiowinter/index.php:17
    0.0003     414256   3. require_once('/volume1/studiowinter/wp-load.php') /volume1/studiowinter/wp-blog-header.php:13
    0.0004     421264   4. require_once('/volume1/studiowinter/wp-config.php') /volume1/studiowinter/wp-load.php:37
    0.0011     485624   5. require_once('/volume1/studiowinter/wp-settings.php') /volume1/studiowinter/wp-config.php:89
    0.0291    3345888   6. require_wp_db() /volume1/studiowinter/wp-settings.php:109
    0.0331    3675688   7. wpdb->__construct($dbuser = 'root', $dbpassword = 'd4LPPARc', $dbname = 'studiowinter', $dbhost = 'localhost:/run/mysqld/mysqld10.sock') /volume1/studiowinter/wp-includes/load.php:435
    0.0331    3676216   8. wpdb->db_connect($allow_bail = ???) /volume1/studiowinter/wp-includes/wp-db.php:639