Both VPS and domain changed but Database URL stayed the same and PHPmyadmin inaccessible to change it

by

The site and home URLs aren’t serialized, if you access to the database export, you can change them directly in that file with a text editor.

You can also override the database values temporarily in wp-config.php with some defines:

define('WP_HOME','http://example.com');
define('WP_SITEURL','http://example.com');