This is the guide from Microsoft

Auto-apply recommendation settings
https://help.ads.microso...com/#apex/ads/en/60121/2 


You can also try these steps:

1. Log in your Bing account

2. Click the left menu "settings" then click "Account Level Options"

3. On the "Account Level Options" screen, scroll down, find the option "Auto-apply recommendations" then click "Auto-Apply Settings". Then you can update your opt-in settings.

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