Give access to your Facebook Business Page so other 3rd party users like us can help with your marketing. Permission allows us to do things like manage users, post on your behalf, advertise, etc. Granting access is the only way to allow this access without having access to your personal login.
First things first, you need to be an administrator of your business page to give this access.
Click Settings at the top of your Page.
Click Page Roles in the left column.
Type firstname.lastname@example.org (or 3rd party name or email) in the box and select the person from the list that appears.
Click Add and enter your password to confirm.