Open the Settings app
Tap Screen Time
Tap Content & Privacy Restrictions
Turn on Content & Privacy Restrictions
Tap Content Restrictions
Tap Web Content
Select Limit Adult Websites
Tap Add Website under Never Allow
Enter the website you want to block
Tap Done
To block all websites except approved ones, select Allowed Websites Only
Add the allowed websites you want to permit
On Mac, open System Settings
Click Screen Time
Click Content & Privacy
Turn on Content & Privacy Restrictions
Click Content Restrictions
Set Web Content to Limit Adult Websites or Allowed Websites Only
Add blocked sites under Never Allow if available
Use a third-party content blocker from the App Store if needed
Install the content blocker
Open Safari settings
Enable the content blocker
Add the sites to the blocker’s block list