Hi tgfree and welcome,
For VSO (default burn engine), as you open Fab, click on the check mark icon (in the green circle) upper right.
Common Settings > Write.
A word of advice...do not choose recommended speed.
I'd recommend that you spend some time on the tutorial:
click on the ? mark icon on upper right of Fab or view right here on cdf on one of the stickies near the top.
Many of us use Img. You can configure Img in its own settings and select it as the default burn engine in Fab.