This is probably a duplicate, but the &@$#& app won’t let me scroll through the suggestions. I keep getting “page is restricted” in Safari for pages that are obviously quite innocent. (Some of them confirmed so by checking on laptop.)
Multiple web pages say Settings: General: Restrictions, but there is no such path in IOS 12.1 and I have so far failed to find anything anywhere in settings. Checked Privacy, Safari, and several other places.
One of those pages claimed to be telling us that it was for IOS 13.