TIP: Postman: To make a query or body parameter appear as a driveable Port on a Flow Request block you have to expose it as a {{var}} variable under the underlying Request settings

Whether and which parameters are exposed on a Request block in a Flow depends on the underlying settings of the associated Request.

If you have a query parameter or body parameter called var you need to set the value field to be a {{var}} under the Request settings (and then always remember to Save). It will then appear as a driveable Port on the Request block in a client Flow.

Can't see it exposed as a Port in the client Flow patch block? Go back to the Request settings and make sure you did a Save!