Below steps are used to add CNAME for your subdomain and TXT records for your domain to verify your domain for custom documentation.
If your domain is managed in GoDaddy or Enom:
Let us assume we are adding a custom domain for "kurmavatar.subdex.space", in this case, the TXT value/ Address is the record data that is provided from Postman.
Points to/ Address will always be "phs.getpostman.com" for your custom domain.
If your domain is managed in AWS: Add the CNAME and TXT as shown below
Once the values are added, it usually takes a couple of hours to 24 hours being maximum for the records to be propagated. You can check if the propagation is successful by navigating to this link: https://www.whatsmydns.net/.
Once you are able to see the values propagated as above, go ahead and click on Verify the domain.
Troubleshooting commonly faced error:
Q) Error message: [RRSet of type CNAME with DNS name <subdomain.domain.com> is not permitted as it conflicts with other records with the same DNS name in zone <domain.com>]
A) CNAME records cannot co-exist with any other records for a domain hence, you will need to edit the existing record type for your subdomain to CNAME or add a new subdomain.