You'll have to do as you were asked: Contact Support so they can explain to you why thedocuments you submitted were not accepted as valid ID.
You can check yourself what documents are acceptable here: https://support.upwork.com/entries/23058042
Only you (and Upwork) know if what you submitted was one (or more) of the following:
"Acceptable documents include passport, national ID card (NIC/CNIC), driver's license, NBI Clearance (Philippines only), tax ID, voter ID, postal ID, or any other valid government-issued photo ID that meets the criteria above. Even when issued by a government agency, we cannot accept documents like student IDs, employee IDs, or library cards."