I’ve been emailing support and generally complaining elsewhere for a couple of weeks about TradeUp.
I got my free share notifications, but nothing had been credited to my account. The complaints stemmed from not getting any responses from their support team.
Anyways, I was checking out the app and my phone slipped out of my hand, and as I fumbled with it, I ended up pressing what I thought was just a picture.

Turns out it was the button to redeem the free stock. I certainly feel silly now that I found this out.
All is well now, I have 3 shares of NIO and 1 share of Ford.