To enable MFA, you will need to download and complete the set up process for the Google Authenticator App (instructions here).
When you have MFA enabled for your user account (see the Users guide for instruction), you will be prompted to scan a bar code after you enter your login credentials:
Once prompted, open your Google Authenticator app, then click the + icon in the upper right of your screen and select Scan Barcode:
After you've scanned the barcode, SoftLedger will be added to your list (as in screenshot above) with a self-refreshing code that will be required for login. Enter the code on your Google Authenticator app when requested from the SoftLedger application: