Currently, the delete option is disabled as per management policy. However, I will forward your request to our management team to consider adding this functionality in the future.
At the moment, based on your current plan, you can add domains, but you cannot delete them from this section. You are only able to edit existing domains.
If you would like to remove an unused domain and add a new one, please click on the pencil icon to edit the existing domain, replace it with the new domain, and then click the save icon on the right side.
Currently, there is no options to check how many domains are active with license from use end.
Thank you.