Overview: Here is a short recording showing how to connect postman to ProjectWise's API's (WSG).
Here is the postman collection: Tutorial on connecting to ProjectWise APIs using Postman
A short video (1.5min) if you want to play with the two endpoint I used:
ProjectWise Posts by me:
Introduction to ProjectWise and BIM
ProjectWise from Bentley - extend with Powershell
Postman Collection to connect to Bentley's REST API for ProjectWise (WSG) (this post)