wrong domain attached to site

If you have access to /wp-content/themes/your-theme/functions.php, you can add the following code:

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

Replace somesite.com with your domain. If you have made links using the incorrect domain, they will also have to be updated to the correct domain.

See this page for details: https://codex.www.ads-software.com/Changing_The_Site_URL

Update. I meant add it to wp-config.php