How to automate the sale of banners and advertising spaces on the site?

Question

Layout

Maybe someone knows how to implement the automatic sale of banners on the site?
Or maybe there is an option to work with some third-party services that allow you to make direct sales (not a third-party context)?

Required functionality:
- The user goes to the banner place purchase page
- Pays for the banner through Free-kassa (or some other option where there are no requirements to be an individual entrepreneur or self-employed)
- Successful payment is checked
- The user uploads an image, a link to the site in special fields and additional text.
- All this is instantly, without prior moderation, automatically published on the site

* The banner hangs exactly until the next buyer performs the same operation;
* Implementation is allowed through the "Posts" wordpress module;
* No additional features such as banner space booking time / analytics / pay per clicks and others - are NOT required.