Hello @lily
Based on the qnty entered … create a list of numbers (use the free plugin “toolbox”)
Send that list of numbers to a recursive api workflow that loops through each number … creating each of the objects that you need.
Here a couple of videos that talk about loop flows (recursive flows). Focus on the looping part and not on the other aspects of what the looping is doing on these videos:
You can also do browser loops using @keith 's awesome free plugin “ListShifter” (I am sure Keith would appreciate some Karma (as anyone would after investing so much time in building such a great tool!) but does not ever ask for it nor require it) 
Hope this helps 