Choosing which Facebook Page you post to
Settings names the Page you post to ("Posting to:"); if you granted more than one Page, Change lets you switch which one EverySqueeze acts as.
Settings → Facebook shows a line under the Facebook card: Posting to: and the name of the Page EverySqueeze posts to. Settings → Instagram does the same for your Instagram account: Posting to @your.account (linked to your Page <Page name>), the Instagram linked to that Page, or a line saying no Instagram is linked to it (see Which Instagram account do posts go to?).
If you granted access to more than one Facebook Page when connecting, the line also has a Change link and a note: 1 of N Pages. Missing one? Reconnect Facebook. Use Change to switch to another Page you granted; a Page that isn't in that list needs a reconnect, picking it in Facebook's window. An assistant sees which Page, but only the account owner can change it.
Change opens a list of every Page you granted, each showing whether it can post and whether it has Instagram linked. The Page currently in use is tagged Current; the one EverySqueeze would pick on its own — the Page that can both post and reach Instagram — is tagged Recommended.
Picking a different Page switches which one EverySqueeze posts to and reads Instagram through. It is one Page for the whole workspace: with more than one TikTok account connected, every account posts to this Page and its Instagram, and changing it changes it for all of them (see Add another TikTok account). This only matters when you granted more than one Page — with a single Page, there's nothing to choose, so the line names that Page with no Change link. A Page you did not grant when connecting is not in the list: reconnect Facebook and pick it there.
After reconnecting Facebook with several Pages granted and none already chosen, this picker can open on its own once, pre-selected on the Page already in use; closing it without changing anything keeps that Page.
See Connect Facebook and Instagram for selecting Pages at connect time, and Reconnect a platform if a previously used Page stops posting.