How to generate a QR Code for Google Authenticator that correctly shows Issuer displayed above the OTP?

I use a different way using a local qrencode installation:

qrencode -o- -d 300 -s 10 "otpauth://totp/YOUR_IDENTIFICATION?secret=YOUR_SECRET" | display

In this way I can rebuild mt lost authentication key library from what I had on my laptop.

The responses recommending usage of Google Charts are absolutely terrible from information security point of view. That's essentially sharing the TOTP secret as well as your username ([email protected]) and issuer (Example) with a third-party company with no legal obligation to keep them secret, and doing that over a GET request! Doing so you violate not only every single assumption underlying multi-factor authentication but also most likely your organisation's information security policy. It nullifies any value added by MFA since the only factor that protects you from compromising your account in case of password breach is itself breached.

Just use any QR code generator as long as it's processing your data locally.

NEVER USE ONLINE QR GENERATORS FOR MFA SECRETS

On Linux I'd recommend the python-qrcode library that can print your QR code using ASCII characters on the console.

pip install qrcode

Then:

qr "otpauth://totp/Example:[email protected]?secret=JBSWY3DPEHPK3PXP&issuer=Example

Warning: sharing your TOTP seed with third-parties breaks the very basic assumption of multi-factor authentication that the TOTP seed is secret.

Just figured this out.

As it turns out, I needed to encode all the special characters in the 'oauth', i.e., '$', '%', '=', etc.

So, using the same Google Charts URL as before, but encoding those characters, like this:

https://www.google.com/chart?chs=200x200&chld=M|0&cht=qr&chl=otpauth://totp/Example%3Aalice%40google.com%3Fsecret%3DJBSWY3DPEHPK3PXP%26issuer%3DExample

And it works correctly.