This is a simple MacOS app I made to practice Swift. It lives in the MacOS menu bar and copies TOTP codes to the clipboard when clicked. It only supports a single 2FA account at a time. TOTP secrets are stored in the keychain.
Want something that supports multiple 2FA accounts, works on all operating systems, and syncs across devices? Check out my 2FA chrome extension: https://github.com/scottmangiapane/authenticator
Time-based 2FA apps generate their tokens by combining a secret key (unique to the user of the website) and the current time. The secret key is usually embedded in a QR code that you scan with your phone. Unfortunately, Menu Bar 2FA doesn't know how to scan QR codes, so you will have to extract it yourself with one of the many existing QR decoding tools.
This gives you an otpauth URL, which will look like this:
otpauth://totp/Example:[email protected]?secret=JBSWY3DPEHPK3PXP&issuer=Example
In this example, the base32 secret key is "JBSWY3DPEHPK3PXP".
The compiled version of this app can be downloaded from the releases page. It is not notarized (the Apple Developer Program is expensive!) so you will have to allow execution in System Preferences > Security & Privacy > General. If you want it to start automatically on login, you can do so in System Preferences > Users & Groups > Login Items.