If a marketplace asks you for proof of acceptance for a transfer that went through tradedesk this information is readily accessible to you. TM does not provide 1Ticket with any information about acceptance.
To find these transfers, log in to tradedesk and click on "tools" at the top of the page, and under tools click "tradedesk"
On the next page, on the left, click "Transactions" and then when that page opens click "transfers"
Once on that page you'll see a list of all of the transfers that have gone through tradedesk, find the correct event/section/row/seat and click "view" on the right. A box will popup showing you if it has been completed which means accepted or if it is pending, which means not yet accepted. Also the C icon on the transfers page stands for "completed" and the P icon stands for pending.
Questions? No problem, 1Ticket Support can help.