If you don't know How To Block Sites On Iphone (https://techzeel.net/how-to-block-a-website-on-iphone/) using third party-party apps then you must follow these steps:-
1. The initial step is to go to the App Store.
2. Now settle on a third-party parental app.
3. Then open and set your logins.
4. Now find the Blocking Website feature.
5. Then finally add the URL in the vacant space.