We recommend your platform to our users for the custom domain service. For the same, we do maintain a document in which we have mentioned the SSL activation steps. But our users are unable to activate the SSL on their own these days as there is slight change observed at the Cloudflare’s user interface. Your services are really awesome & we do support Cloudflare only. Therefore, please help with the latest steps for SSL activation on a custom domain as per the current UI so we can share the same with our users.
I had a conversation with one of your users recently here:
The issue turned out to be an invalid certificate on your side for the custom domain. A valid cert needs to be served on your end for Cloudflare to validate, to properly secure the connection between Cloudflare and you.