My website has a critical error

[BeatrizNunes]

My website link is beatrizilustra.x10.mx. how can I solve this? I have a backup from a plugin

 

[mrburnsx]

If you truly have a full backup of everything of your Wordpress, then you can use Softaculous to remove Wordpress completely, install a fresh Wordpress and use that backup to restore it.

 

[fusio]

It depends with which plugin you made the backup!! but your domain name has nothing to do with backups.
Try suspending and then deleting that domain and creating a new one with the name you prefer, then backup your normal site.
Tip: if you use WordPress, the best plugin to make backups is Duplicator.
I hope it helps you