API integration and Order Flow Diagram test.

I’m interviewing for an Implementation PM role and will be tested on API integration and given a task to create an order flow diagram. I have been implementing software for years, first as an associate and then a PM, but have no experience with API integration and have never made an “order flow diagram”. While the hiring staff said the tech knowledge doesn’t matter as much as management experience, I would still like to prepare for this test.

Do any of you have experience with API integration?

Do any of you have experience making Order Flow Diagrams?

Does anyone know what to expect from this type of test?

If so, would you provide simple examples and/or tips?

All help is appreciated. Thank you.