How to update contract owner with the api ?

How to update contract owner with the api ?

Hi im trying without success to update contract owner during the creation of contract or after with the 'PUT' operation..

Ys i can attached collaborators, but i realy want this users to be the owner of the contract ! 

But i cant succeed to get the correct Key i think ..  Is this even possible ?

  2. ownerEmailId = "ZOHO CONTRACT EXISTING USER EMAIL";

    {
  3. "inputfields":[
  4.   { "metaApiName":"owner",
  5.          "inputs":[
  6.             {
  7.                "inputApiName":"email-id",
  8.                "inputValue": "ownerEmailId"
  9.             }
  10.  ]
  11.     }
  12. ]
  13. }
I always get the : PATTERN_NOT_MATCHED Error.. as i guess some key was incorrect..

Any Helps ?