You will start by going to your Facebook account. Followed by that, you will head over to the top right avatar icon with your profile picture in it and then head to "Settings and Privacy".
Inside "Settings and Privacy", click on "Settings".
You can follow that up by going to Business Integrations on the left:
Once there, please click on "view and edit" in front of the LeadConnector app:
Please make sure that all the toggles are turned on; scroll down all the way and toggle everything on:
When a list of pages shows up with checkboxes in front of them, mark all those pages that are relevant to your accounts.
Once done, please click on "Save".