You can use this tool to tell the search engine about changes to your site's domain name or protocol, and to choose the preferred way to show your site in search results — with or without the "www" prefix.
Using this tool requires correct settings for the main mirror, which may be a redirect or a Host directive in the robots.txt file on all the site's mirrors.
The migration may result in changing the site's main mirror or combining the appropriate mirrors in a group if they weren't previously grouped together. You can check whether the site is a secondary mirror.
For the new site address, you can choose any name from the list (it displays all the resources that have been added to the service that you have confirmed management rights to). If necessary, you can enter the "www" prefix or the "HTTPS" protocol.
After saving changes, the information is verified. As a result of verification, your request will be approved if the content of sites that the robot gets is identical and the main mirror settings are valid, or rejected if the requirements for grouping sites are not met.
Possible reasons for rejecting changes to the site address:
Changing the address may take some time. Yandex cannot guarantee that the site will have the same number of pages in search, the same position, or the same traffic after the main mirror has been changed or mirrors have been grouped together.