POSTMAN material for APIC-EM. There is a tutorial here:
And a Postman collection here:
APIC-EM has multiple roles and you can have external (radius) accounts or internal accounts.
The postman collection uses variables for the username/password and the first request is to get a ticket, which is then used for all subsequent requests.
Here is a blog posted on the using the postman collection Look No Code... learning about APIC-EM API without writing code...