If 1Blocker extensions appear greyed out in Settings > Safari > Extensions, it seems that you have some restrictions enabled on your iPhone.
No worries, you can manage them easily, and here's how to do it:
- Go to Settings > Screen Time > Content & Privacy Restrictions (enter your passcode if required).
- Scroll down to the Content Restrictions section.
- In Content Restrictions, go to Web Content. You'll need to set it to Unrestricted Access in order to activate 1Blocker. Alternatively, you can just turn Content & Privacy Restrictions off.
You should now be able to turn on 1Blocker extensions in Settings > Safari > Content Blockers.