Quick search came up with this: https://play.google.com/store/apps/details?id=com.watchfacestudio.az261jsoncodewatchface
Quick search came up with this: https://play.google.com/store/apps/details?id=com.watchfacestudio.az261jsoncodewatchface
Works for me as a preview in the comments, but tapping on it just shows a black screen.
Proton has a business plan, too.