Hi,
I created a new app in atlassian marketplace, that also got approved. However, since the beginning I try to change the payment plan from free to a paid plan. However free is always greyed out and I can not do any changes. Also created a new version now, and still can not change the payment model:

Online I only found some outdated documentation, where it says I need to go to the payment tab. However, as you can see there is no payment tab.
Can anyone help?