You can use a laptop with a webcam and a mirror to use a web QR code scanner. Usually the TOTP code is displayed under the QR .-.
They can also use WinAuth https://github.com/winauth/winauth
Or for Linux you can use https://github.com/paolostivanin/OTPClient
The desktop app will let you scan QR codes that appear on screen. When 2FA fields show up, the password autofill shortcut (cmd + \ is the default I think) will automatically populate them.
I like having TOTPs stored this way, as you can use them with any device, including over NFC on Android, just by installing the Authenticator app.