Create user via moodle web-service API

1) Assuming, that your moodle has been configured properly - a little bit outdated example is here:
https://azhowto.com/creating-a-moodle-user-via-web-services/

2) Actual call via postman

3) Response:
[
    {
        "id": 14,
        "username": "asdf"
    }
]

4) Source for inspiration:
https://ethinkeducation.com/wp-content/uploads/2019/09/Creating-Your-First-Web-Service-Integration-from-Core-APIs.pdf