To grant Facebook Messenger access to stored credentials on your MacBook Air running Monterey, you can follow these steps:
1. Open "System Preferences" from the Apple menu or by searching for it using Spotlight.
2. In System Preferences, click on "Security & Privacy."
3. Select the "Privacy" tab.
4. From the list on the left, select "Passwords."
5. You may need to click the lock icon in the bottom left corner and enter your administrator password to make changes.
6. Scroll through the list of applications until you find Facebook Messenger.
7. Check the box next to Facebook Messenger to grant it access to stored credentials.
8. Close System Preferences.
By completing these steps, you should have granted Facebook Messenger the necessary permission to access stored credentials on your MacBook Air.