Ok. QRadar doesn't allow you to create offense (for elk, it could be alert) directly via API.
Offense api in fact introduced in the latest version (16) of the QRadar api. You can check for available options here.
https://www.ibm.com/docs/en/qsip/7.4?topic=160-siem-endpoints
IBM® QRadar®7.4.3 introduces version 16.0 of the API endpoints.
#QRadar#Support#SupportMigration