The transfer of the site from the test domain to the main

There is a ready-made website on WordPress, which is a test domain. When you transfer it from a test on the main I theme settings that allows you to complete the transfer.
The task consists in the following:
1. To migrate a test website on a WP test from one domain to another
2. To move the site to the current working domain.

All access and other necessary points will be provided to the selected freelancer.