Recently went through this when my teen went to a game with friends. From my experience, it seems like your best bet is to just drive up and pay at the lot when you get there.
I tried buying a parking ticket through Vivid seats the day of so she wouldn't have to worry about it and would be close to the field. They sent me multiple emails, but never sent the email to transfer/access the ticket. After two unsuccessful chat attempts and one unsuccessful phone call attempt I gave up. She tried to use the receipt email and it, as expected, did not work. She was able to just pay to park in that same lot.
Ironically, the drive up charge to park in the lot next to the stadium (B or M iirc) was $30. After fees and crap I paid $102 and change for the ticket I never received. Stupid, I know, but I haven't personally been to the new field either and had no clue on parking prices nor did I find them listed anywhere online.