How to get a picklist value and copy it to other module picklist?

Hi,

I'm new in Zoho function. Could you help me with the function?

I would like to get a picklist value from Account module and copy it to the same picklist in Deals module. The field is named Customer in both modules. What can be important, the picklist is a Global list.

I've tried with the following code

cnRec = zoho.crm.getRecordById("Accounts",input.accID);

updateMap = Map();

updateMap.put("Customer",cnRec.getJSON("Customer"));

updatedCustDeal = zoho.crm.updateRecord("Deals",input.dealsID,updateMap);

It doesn't work but does it make any sense? Is it a good direction?

Any help is welcome.