Hello,

So there isn't a supported way to create new Participant Groups via the Javascript API, but there is a way to do this. I'll send you the information directly, but please keep in mind that we don't guarantee it working consistently since we can change how the platform works when it comes to this. Essentially, the Participant Group is handled by the ParticipantGroupController within the Study module and the CreateParticipantCategory action handles adding the category along with the group.

Regards,

Jon