I'm using beatbox API to update/insert data in to salesforce opportunity object.
upsert() throws INVALID FIELD error when I pass Id as externalIDFieldName. Currently I'm using another unique external Id and it's working fine but I want to use the salesforce Id.
Please shed some light on what I'm missing.
If you already know the salesforce Id of the record, just call update instead.
upsert throws error when I pass Id as externalIdFieldName in Beatbox API while contacting Salesforce