List JIRA app on marketplace

Hi all,
I have hosted my app on Heroku and private Listed the app on JIRA Marketplace. Now, what steps are needed in Heroku for my app? Is it mandatory to purchase Heroku? and what steps are required to make my app Public?
Thanks

Since this is a hosted app I believe you are referring to Jira cloud?
I suggest adding relevant tags so the question becomes more visible to people following those tags