Hi @james377,
Trust you are doing good and thank you for reaching out to us.
Once you have activated Defender Two Factor Authentication, you need to enable the same for the user under the User profile edit page. For that, please navigate to WP Dashboard >> Users >> All Users and find the edit option of your profile. Now you can see the option to enable the Two Factor Authentication as in the following screenshot: https://ibb.co/rpVtcW5
Please find more about the same here: https://wpmudev.com/docs/wpmu-dev-plugins/defender/#two-factor-authentication
Feel free to get back to us if you still notice any issues.
Kind Regards,
Nebu John