After restoration of backup, I am redirected to /wp-admin/install.php

Yesterday I tried restoring an older backup of my website through the panel of my hosting provider, following their instructions. Ever since, when I go to my site, it redirects me to /wp-admin/install.php.

My hosting provider has contacted me saying that something went wrong and they are fixing the problem. However, it’s been almost a day and I have no news from them. Does anyone have any idea why this happened and if there is something I could do to fix it?

Thank you!