Custom Domain
Add an Extra Custom Domain to Your Workspace
How to connect additional custom domains if you’ve exceeded the limit.
If your workspace has exceeded the available number of custom domains, when you try to connect a new custom domain to your Softr app, you’ll see a pop-up with some details on the extra domain and a Confirm button.

As soon as you click confirm, the additional fee will be added to your billing and you’ll be able to use the new custom domain.