Connecting your Facebook page means guests who message you on Messenger arrive in the Unified Inbox alongside every other channel, rather than in whoever happens to have the Facebook app open.
You have to be an admin of the Facebook page. Not an editor or a moderator. If you are not, the connection cannot be completed, so find out before you start rather than halfway through.
Connecting your page
Go to Settings > Channel Integrations, or open platform.bookboost.io/#/settings/channels.
Select Messenger.
Select Link your page. You are taken to Facebook.
Choose the page you want to connect, and leave every permission checked. Unchecking one usually means messages stop arriving, and it is not obvious which one did it.
Facebook returns you to Bookboost, with the page linked.
Go back to the Messenger integration page and activate the page. Linking and activating are two steps, and this is the one people miss.
Confirming it works
Message your own page from a personal Facebook account and check that the conversation appears in the Unified Inbox. If it does not, the usual cause is step 6: the page is linked but not activated.
What this does not do
It does not work without admin rights. Page admin, on the Facebook side.
Linking is not activating. A linked page that has not been activated sends nothing to Bookboost.
It does not move your message history. Conversations that happened before the connection stay on Facebook.
It does not take over from another provider automatically. If another tool is already connected to the page, there is one more setting on Facebook's side. See Facebook Messenger: switching from another provider.
What to do next
If your page was previously connected to a different messaging provider, do the handover step as well, or messages will keep going to the old tool. See Facebook Messenger: switching from another provider.
Getting help
Open Help at the bottom of the left menu and choose Talk to Us, or email support@bookboost.io.