We get this question a lot. If you already have an existing Cloudflare account it makes sense to move zones (domains) to your Servebolt provisioned account. Unfortunately, this is not possible to do in an automated fashion.
You’ll have to add the zone to your Servebolt provisioned account as if it hadn’t been added to Cloudflare at all. All the settings and configurations should be recreated in the new account. It doesn’t matter if you have a Cloudflare Free, Pro or Business account in this matter. You will always have to manually add and rebuild the zone in the new account.