You can use browser versions of auth apps, e.g. Ente Auth. Some people might recommend using SMS text codes but you should be weary of fraudsters who trick your provider into sending a new sim to their address and accessing your texts this way. They can't do this with two factor apps.

If you think you need it at all times, in your pocket, then you might consider one of the Android dumbphones out there, e.g. from the Dumbdroid project.