Upgrading on A321T

So I booked my first A321T transcon in about two weeks. I can't find a place on the website to upgrade with miles (although not likely available). Is there a way to do it without calling? Is there a way to see availability on line other than the seat map?

Thanks!

 

I'm no expert, but when I did a miles+co-pay upgrade on a recent international flight, I had to call. There was no telephone charge.

 

Upgrade space is searchable at Expertflyer, you cannot confirm an upgrade with miles online you will have to call.

 

Thanks Gary, and Happy New Year.