Blank page – Godaddy says it's WordPress

Hello,

All of a sudden, my site totally disappear. If I go at https://www.muffleretgazoline.com it’s a blank page. No error message, nothing. Same if I try to access my control panel via https://www.muffleretgazoline.com/wp-admin

I called GoDaddy and they told me everything was fine on their side. So they told me I might be WP, a pluggin or a theme update.

How should I desactivate or switch theme via a file manager since I can’t access control panel.

I’m using mag.Press them from Obox.

Thanks!

CEC