To link your Instagram account to Facebook, open the Instagram app, go to your profile, and tap the menu icon in the top right. Select Accounts Center, tap Add accounts, and follow the prompts to log in and connect your Facebook account.
Linking via Accounts Center
Open Instagram and go to your profile.
Tap the menu icon (three lines) in the top right corner.
Tap Accounts Center.
Select Sharing across profiles or Add accounts.
Choose Add Facebook account and log in with your credentials.
Tap Continue to confirm and finish the link.
Connecting a Professional Account to a Facebook Page
Switch your Instagram to a Business or Creator account if needed.
Go to your profile and tap Edit profile.
Under public info, tap Page and select Connect or create.
Log in to Facebook and select the specific Facebook Page you want to link.
Tap Connect to finish pairing the assets.