This is from the Dometic Power Awning Manual,
In Case Of Coach Power Failure Or To Manually
This procedure will require two people. When this procedure has been performed, the awning must be serviced by a Dometic Service Center or a qualified service technician before using again.
1. Slide the pull strap (provided) into the utility slot of the FRTA.
2. While one person is holding onto the pull strap, remove the screw in the top of the right top casting.
The FRTA will immediately roll in once the bolt is removed. Walk the awning to the closed position.
3. Align hole where screw was removed and replace screw into top casting to secure awning.
Screw must be re-installed to prevent awning from opening during travel. Have awning serviced by a Dometic Service Center or a qualified service technician before attempting to open awning after this procedure has been performed.