If you would like to set transactional log backups, you have to set the Verba database recovery model to full.
To change the recovery model to full:
Step 1 - Start SQL Server Management Studio or SQL Server Management Studio Express.
Step 2 - After you connect to the appropriate instance of the Microsoft SQL Server Database Engine, in Object Explorer, click the server name to expand the server tree.
Step 3 - Expand Databases. Select Verba database.
Step 4 - Right-click the database, and then select Properties.
Step 5 - On the left pane select the Options page and set the Recovery model to Full.
Step 6 - Click OK.