Hello, Is there any way I can create a POST endpoint to store some data that can be used to do a GET later on?
The simplest way is to use a data bank. The data bank tools will save data that can then be used in the response from a different responder. This is will work for simple cases where there is no need to support concurrent requests, e.g. two POSTs then two GETs.
If you need a more complicated setup that saves state look at this documentation for the Data Repository CRUD Tool.