Facebook Messenger Chat FAQs
How is the chat app linked if there are multiple Facebook pages under the same account?
If you have multiple Facebook Pages linked under your account, you need to select the page you want to connect to the app. If you have already linked your account and wish to change the page, unlink your Facebook account from the app and re-link it.
The permissions screen should re-open every time the account is unlinked and then linked again. However, on subsequent authorizations, Vitals will collapse the pages into an "Edit Settings" window. If that button isn't clicked, the previous authorization will be used, and Vitals will pick up only the last selected pages.
Why can I see the app only when I'm logged into Facebook?
This happens because the Facebook page isn't yet published, and you can see the Facebook Messenger Chat Plugin only when you log into Facebook as it detects you are the page's admin. The obvious solution is to publish your shop's Facebook page. Check the Facebook guide on publishing pages here: How do I unpublish or publish my Page? | Facebook Help Center | Facebook.