Backup not working

So I’m starting a new website and I wanted to try a few things. I’ve installed the basic plugins that I always used and then I’ve tried to create my first backup. Suddenly It didn’t even start.
Asked the name I wanted and then… nothing.
“SOMETHING WENT WRONG
Oops… Seems there was an issue during the backup process.
Please try again. If the issue persists, please contact our support team.”

I had the

“BackupGuard Warning: Your website is running on a LiteSpeed server. If you are experiencing problems while backing up or restoring, try to add the following code to your .htaccess file”

So I did that on .htaccess and then I had no message, but didn’t work again.

I thought, ok. Maybe I did something different?
I went to a different website, in which I had not updated anything since the last backup, same server (with the same message “LiteSpeed server”) and doesn’t work.

I can say then I have no idea what went wrong.