We are having issue while creating a custom object record along with TSV attribute's data.
Release : 16.0.3
TSV data can't be passed in the JSON body of the POST request. You can to create the record first and then update the TSV field with the data using a PATCH or PUT API call.
Sample :-
PATCH :- https://<host>/ppm/rest/v1/ideas/{{recordId}}
BODY :- {"d":[{"{{API_ID_Attribute}}":{"workEffortUnit":"hours","pattern":"uniform","periodList":[{"periods":[{"start":"2023-01-01T00:00:00","finish":"2023-01-31T00:00:00","value":10}]}]},"_internalId":5000000}]}