Renaming a 3rd level domain - *.bitrix24.*, for example, from example.bitrix24.com to test.bitrix24.com, is possible only for Standard, Professional and Enterprise plan users.
To change the domain, the Bitrix24 administrator should create a request to technical support and specify the name of the old domain and the name of a new one.
Note that after changing the domain, the following services will stop working:
- Open Channels - they should be reconnected.
- All widgets on websites (Online Chat, CRM forms, callback) - they should be reinstalled.
- Application webhooks - they will need to be recreated.