If a bid is applied on the traffic source profile page for Facebook, the campaign will launch with a bid cap. If one is applied for a Tik Tok profile, it will set a target CPA. If a bid is not applied on the traffic source level, then the camp will launch at highest volume.
If you launch a Facebook campaign with a bid cap, then adjust the bid on the campaign analytics table, that bid cap will turn into a cost per result goal.