thank you for your post.
Unfortunately Yubikey is not working with TeamViewer 2FA, only Authenticator Apps that do support Time-based Authentication works with our software (https://en.wikipedia.org/wiki/Time-based_authentication)
We reccomend to you to use Google Authenticator,
for Android you can download it here: https://play.google.com/store/apps/details?id=com.google.android.apps.authenticator2&hl=en
for iOs from here: https://itunes.apple.com/us/app/google-authenticator/id388497605?mt=8
Enjoy using TeamViewer and it's good to hear that you do care about security like we do!
I love security, but I hate the Captcha used.
Hoped to get rid of those annoying pictures by using yubikey without installing apps.
Thank you for your reply
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