Learn about changing the domain name in your SharePoint and OneDrive URLs
You’ll be able to change the SharePoint domain name for your organization in Microsoft 365. For example, if the name of your organization changes from “Contoso” to “Fabrikam,” you can change contoso.sharepoint.com to fabrikam.sharepoint.com.
Preview date: November CY2021
Source: Change your SharePoint domain name – SharePoint in Microsoft 365 and https://docs.microsoft.com/en-us/sharepoint/troubleshoot/administration/domain-rename-faq
and https://docs.microsoft.com/en-us/sharepoint/troubleshoot/administration/errors-when-renaming