Author certificate error help

When I try to get author certificate here is the error I get. Not sure what it is
Screen Shot 2023-07-22 at 11.03.40 PM

Are you talking about Watch Face Studio? Could you please clarify?

As per your this ticket Having problem getting certificate to test watch face, you are using Mojave/Ver: 10:14:6/Mac Pro.
Please check the Watch Face Studio Mac requirements Watch Face Studio does not support macOS 10.x any longer