520 error on my page

I don't know why my page pushs the 520 error, the thing is when I open my page from localhost or ip it works (when cloudflare is paused). Some help please. I've been checking for two hours and i don't what to do.

Page: ticketsmanagers.app
Account ID: 52797855300a3285cc3f9e180c0b6bae
Error: 520