The layer for the Transport Mode is below your channel layers.
Use a fast 3 finger double tap to enter or leave this mode.
Now you have access to all additional transport controls, like forward, rewind and main fader volume.
You can enter the Transport Mode from the Channel Strips with a
fast 3 finger double tap anywhere on your screen.
The user interface will automatically animate to the Transport Mode screen.
When you're done, use the same gesture, to leave this mode.
This gesture can be used with a 2 finger scroll left and right .
Depending on your current DAW, you might end up with an automatic forward or rewind behavior until you release your touches, or with a 1:1 forward / rewind like a jog wheel.
The volume of your main fader can be adjusted with a 1 finger scroll up and down, just like you
change the volume of your channels.
If you use a second finger next to your volume finger, you can enable the Volume Trim feature, which gives you a more precise handling of your volume.
The main fader might not be available in all DAWs.