API Upsert not working

Hi There,

We are testing this API Upsert

https://apisalesdemo8.successfactors.com/odata/v2/EmpPayCompNonRecurring(payComponentCode='BASESAL_US',payDate=datetime'',userId='LOA01')

for Off cycle payment but it is giving error

"2022-11-14T10:08:08.425844Z    stdout: message: 'EC Upsert failed! 

But there is no failed records return from import engine! error message:

The system has encountered an unknown error on import. Please contact the System Administrator.',",

Can you please check or suggest what is going wrong.

Thanks,
Jyoti