Can I play among us on ubuntu?

Yes, at least on my machine.

• Install Steam and buy the game.
• Force the use of Proton.
• Configure the Launch Options (from here, step 4):
  PROTON_NO_ESYNC=1 PROTON_USE_WINED3D=1 %command%
• Install the game.
• Start the game -- may download additional dependencies (e.g. Proton).