Update fields by updating a selection list

Update fields by updating a selection list

I have a form with several fields (forming a timeline of my request) and a selection list field.

I need a code so that when I change the selection list it updates one of the fields. Fields are checkbox

I tried something with this code but without success:

AcctDetails = zoho.crm.getRecordById ("Quotes", input.acctId);
AcctId2 = input.acctId.toString ();
Mp = map ();
If (input.product == "Trial TRT RO")
{
Mp.put ("Trial TRT RO", true);
Resp = zoho.crm.updateRecord ("Quotes", acctDetails, mp);
}


Thank You