I can’t turn off limit ad tracking

If you have seen the GIF posted by me and If it still doesn't work. It could be probably that a Profile is installed by your organisation / enterprise / corporate through device management and have disabled it.

Contact your system administrator in your Organisation.

1) Go to Settings

2) Tap Screen Time

3) Tap Content & Privacy Restrictions

4) Turn on Content & Privacy Restrictions

5) Scroll down to Advertising and choose Allow

6) Go back to Settings > Privacy > Advertising and turn off Limit Ad Tracking.

If it is greyed out!, This may sound silly but it works.

Watch this GIF below to enable it.