Before you schedule posts to Facebook, make sure you have added your Facebook Page to your Apphi account.
Important: To add your Facebook Page to Apphi, Facebook requires your personal Facebook account is the admin of the Facebook page, and you currently have your personal Facebook account logged in on your phone.
Open Apphi app > go to Settings > tap Added Social Account > tap "+" button on the top right corner > select Facebook Page
Click "Continue" when you see the popup window to sign in your Facebook. You can log in with Facebook app or with phone or email.
Click "Continue with ..." and toggle on the Facebook Page you want to add to Apphi. Don't forget to toggle on "Manage your Pages" and "Publish as Pages you manage". Tap "Done" to finish.
Note: If you don't see the Facebook Page you want to add in this step, please make sure that page is under your Facebook account on your Facebook app. You can open your Facebook App and tap the bottom right corner to see if the Pages are under your name.
Your Facebook Page is linked to your Apphi account, and you can now schedule posts to your Facebook Page!