I have a Cleric that has taken brew potion as a feat. There is no mechanism to add potions created to the inventory like adding a scribed scroll. For a scribed scroll I use the –add custom scroll in the Magic Tab to create a scroll. It gives me the cost of scribing the scroll based on the spell and Level I select (See Image). There needs to be the same thing for creating Potions as well. You should be able to use the same code modified for potions instead of scrolls.