Hey @martin2,
As Nigel suggested, the way to go about this is to Schedule an API Workflow on a List. If you install the Toolbox plugin, you can use the List of Numbers element (it gets added to your elements) to generate a list of numbers. Set the start number to 1, the list length to the value of that dropdown, and increment by 1.
Then, off a button click, Schedule the API Workflow on a List. The list being the value of this List of Numbers element. If a user selects 5, for example, the the list generated would be 1, 2, 3, 4, 5. With that, the API Workflow can be set up to create a new Payment (and anything else). For every item in the list, it will run that workflow.
I have a video on this action which can help walk you through it. Keep in mind that, in your case, your list is what I described above.
Check out the tutorial here: https://youtu.be/LLYaNHmt6_Y
Gaby | Coaching Bubble
Private coaching, courses, and tons of free resources