After you file
normally Desktop and Online are separate, but there's an offer this year to switch your desktop license to Online Premium Fed+State at no extra cost. The offer is displayed when you install the s/w on Win 10 (see below). But it's one way, if you do this you will no longer be able to use the desktop s/w, say to install on Win 11 later. I can't speak to the mechanics of how the offer is applied but think there is somewhere to enter your license code.
Online is not the same as Desktop - you're probably seeing that already if you got to the payment stage - no Forms mode, and you can only prepare 1 return. It's usually more expensive than desktop especially if you have multiple returns.
For more info on Desktop vs Online see comments from @VolvoGirl at the end of this thread
More info:
