Hi, in my pc, Anki Desktop has 2 decks contained in 2 different profiles, and I can switch between them, but Ankiweb just shows me one of them and don’t know how to switch from one to the other one, and it also happens in my AnkiDroid.
Each profile is a separate account. You can’t have multiple profiles saved on the same account, only one of them will get synced, and ankiweb/ankidroid will only show one profile at a time.
If you want to use both decks in the same profile, export one of them and import it to the other profile so that you have all your decks in one profile.