While I am creating ticket. I want to give in" Organizations" Below as "Three UK". It is not in organization drop down field. so, I want to add "three Uk" filed in drop down of organization filed. is it possible to do using with rest API Key?
while I am trying to add Three UK field in drop down of Organizations field using rest API I am getting below error.


{"errorMessages":[],"errors":{"organisation":"Field 'organisation' cannot be set. It is not on the appropriate screen, or unknown."}}
please advice me if we have any feasible ways to do this using with rest api keys
Thank you