Help with python using requests (info inside)

So I'm using a private API I wouldn't be able to send the code of here's what I need: I'm trying to post data for IDs there are two (2) ids for every item one is a static id eg '150000' and the other is randomly generated eg '7515641' the 75 portion of the will never change. What I need is to post the data to sell an item with the static id but to do that you need to post the generated id - I need someone who would be able to do that so for example: I have 3 items, static ids are: 150, 250, 350, to sell them I need to post the generated ids of let's say 75000, 75555, 75985. Is there a way to do that based on the static ids and pass the generated ids into the post? This would need to be done for multiple ids possibly 300+ though as long as you can provide me with the way to do it I'd be more than happy to manually add all of the static ids in myself! Provided a small photo of a snippet as an example, it's all in json - there is no actual website either so I wouldn't be able to send you a link. I can provide as much information as possible for this.