Navigate to [my.slack.com/account/settings](http://my.slack.com/account/settings)

Scroll to "Multifactor Authentication" under "Account" and click "Expand"

Select your preferred authentication application or SMS text message (note: some authentication applications may cost money--SMS is recommended)

SMS Text Message
Receive a text message to your mobile device when signing in.


You may be prompted to authenticate via Google SSO--if so, go ahead and sign in