did you check standard documentation?
and community posts :
Just now I got some relevant information about the operations:
Create operation will work for new user, if you want to push modified users then you need to create Set operation
Thanks for your kind response.
Please could you provide detail for the new user scenario.
Suppose if that user is not existing in the CTM:People form then how with his/her details we can raise an Incident??
Early response will be highly appreciated.
For your scenario, guest users should be enabled in the system to create incident for the users which does not have people record. Or you can create the user first and then raise the incident.
Create Operation for both user and incident creation.