Step 1, Navigate to Facebook.Step 2, Open the Facebook menu. This is the downward-facing arrow in the top right corner of your Facebook page.Step 3, Click “Manage Ads”. If you don’t have an ad account yet, you’ll need to click “Advertising on Facebook” instead to set one up.
https://www.wikihow.com/Reclaim-Admin-Rights-to-a-Facebook-Page

