To modify mode, click Authentication Mode and then click Modify Authentication and select your preferred mode and verify it by following the steps for enrollment.
Click Trusted Browsers to view the list of browsers marked trusted. To remove, select one or more browsers and click Delete.

This option is available only when two-factor authentication is enabled by your admin.
Each backup verification code can be used only once and make sure that you generate a new set of backup verification codes before using all the codes in the existing set.