Using cookies in vCenter Orchestrator HTTP-REST plugin possible ?

I want to use the HTTP-REST plugin contained in vCenter Orchestrator.

I have to invoke a service by REST api, but a value has to be set as cookie in it's api (not as input parameter).

Is it possible to use cookies in the HTTP-REST plugin ?

If I execute the workflows "Add a REST operation" or "Invoke a REST operation" I can't find any input fields ?

I'm using vCenter Orchestrator Version 5.5.2 (and 5.5.1).

Thank you for any help!