Cant access wp-admin

Question

After changing the site URL in settings I am no longer able to access the wp-admin page. When I enter the new URL it says:

Not Found. The requested URL was not found on this server.

I am no sure what to do now.

Edit: Tried to add the following lines to wp-config.php file but it didn’t help

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