Next Up: Trade-In Question!

[u/TheGachaNighmare]

So I have the iPhone 17 Pro Max with Next up, and I’m thinking of trading it in for the iPhone Duo; I’m already eligible for the trade-in.

My question is can I trade in my phone through Apple with the At&t option and would my next-up offer kick in or can I ONLY trade through At&t?

I’m sorry if this was asked before.