I need a backup on my safari app

Your question is not clear to me. You can restore a backed up item using Time Machine but that is not related to Safari.

Could you explain what you need to do?

That website has been prevented from loading. Refer to "Prevent web content" in Use parental controls on your child's iPhone, iPad, and iPod touch - Apple Support.

The website may also have been restricted by your cellular service provider "MTN".