I don't use cloudron and I only commented as when I was looking for the specific cloudflare error:
I landed here from Google and I know that in the future, I will probably have this issue again and forget the solution.
So I'm posting this more for future me.
However, this would solve that specific issue that @girish was having,
I got my services up and going that used a self signed ssl cert and was able to proxy it with cloudflare.
It would be cool to try cloudron as it sounds like a really great product, but I personally don't have the budget for it at the moment.