Hello Lisa!
This is Margalo, a Shopify Guru from the Support Team. :)
So I'm wondering if you could try installing the Facebook app again by following the instructions found here: https://docs.shopify.com/manual/more/official-shopify-apps/facebook-store
Just make sure you're logged out of your personal Facebook account before downloading the app. I would try that and then let us know what happens.
Thanks!
Margalo
Shopify Guru
