The zone you are trying to upgrade is marked as Do Not Upgrade.
What is the issue you’re encountering
I’m trying to add a .cc extension domain to my account but I’m getting the following: Refer to https://cfl.re/3VUQyyL for assistance. The zone you are trying to upgrade is marked as Do Not Upgrade. (Code: 1315). Why this?
What steps have you taken to resolve the issue?
I created another CF account but still didn’t work.
That is to be expected. The domain is flagged, making the account used irrelevant. You will need to follow the instructions that you shared in your post.
Yes you can. In fact, you have to. It is the only way to resolve your issue. All plans are able to open support requests for account, billing, and registrar issues. You will need to open a billing support request.