Add multiple admin in facebook page -

Facebook access means:

You can switch into the Page and manage it directly on Facebook, or by using other tools like Meta Business Suite or Creator Studio. View Tools
Any action you take as this Page, including on ads or when checking into a location, may be visible to anyone else who manages it. Learn More ....
Anyone with Facebook access will have a shared experience, including your Feed and your notifications for this Page. However, each admin will see ads that are personalized to them based on their activity across Meta products. 

You can give access of your facebook page to others . https://www.facebook.com/settings/?tab=profile_access

Make Sure Your Page Activated As Profile