I do this stuff manually in autohotkey for flows like tabbing to the MFA app window, clicking the right place to copy the code, tabbing back into the app I'm trying to log into, clicking the right space to get to the input fields, and entering the username/password/mfa. As well as for logging onto a website where I need to enter the username, hit tab, hit enter to select "log in with password", then enter the password and hit enter again. Saves a lot of time/dealing with typos in the unnecessarily complex passwords these systems require and it's cool to watch it do it.
If you set a master password for saved logins in Firefox then passwords won't be available with a simple click, and they will be encrypted on disk.
In browsers that use the OS' password storage then they will normally be stored in encrypted form, although the browser integration is seamless so you won't notice the difference.
In both cases, there is a significant security advantage in cases where the data on disk is leaked (say, if someone steals your computer and you don't have full-disk encryption.