How to get credential
In order to see the Credential Username value, add the parameter $expand=RobotValues to your API call. RobotValues needs to be expanded for the GET Assets or GET Assets (ID) to return the username.
Example as below:
supermanPunch
Yoichi
Anil_G
fernando_zuluaga
ppr
Sudharsan_Ka
Shera
john_johnsen
muthuraman.g
Jack_Tsang