1. From Setup, enter Domains in the Quick Find box, then select Domains.
2. Click Add a Domain.
3. Enter the domain name.
4. Choose the HTTPS domain configurationoption you want to serve this domain with. Optionally, specify a CNAME value if you’re using a non-Salesforce provider to serve your domain.
5. Add a certificate if you have already set up a CA-signed certificate that supports this domain.
6. Click Save. To add another domain, click Save& New.