Creating a post with a Branded Content sponsor
To make a Branded Content post on Facebook, your Facebook Page must be an approved Branded Content partner on your sponsor's Facebook Page.
Your sponsor will need to enter your Facebook Page name in the Approved Partners Box in the Branded Content section in their Meta Business Suite. This section is located in the Monetization tab under Branded Content.

To add a Branded Content sponsor to your post in SND, simply click the Branded Content button in your Post Composer.

In the Branded Content search bar, type in the name of your Branded Content sponsor and select your sponsor for the drop down.
Add content and schedule your post or post now.