I can't post to a Facebook brand Page.
Right now, it isn't possible to post Instagram photos directly to a Facebook brand Page from an Android phone.
To link an Instagram account to your brand's Facebook Page:
- Make sure you're an admin on the Page.
- Go to your Profile tab > > Share Settings and then tap Facebook.
- Link Instagram to Facebook on your phone. When the Facebook authorization appears, make sure that the Facebook username at the bottom is an admin of the brand's Facebook Page.
- If you've already linked Facebook on your phone but need to switch accounts, unlink your Facebook account from Instagram.