Get a spray bottle of Tilex or other cleaner that contains bleach or make up your own - cup of bleach per gallon. Spray the top of the awning with the mixture then roll up the awning which will coat both sides of the awning. Let it sit for a while, then unroll rinse and let dry. IF you have stubborn spot, spray and wipe them directly.
Tom Wilds
Blythewood, SC
2016 Newmar Baystar Sport 3004
2015 Jeep Wrangler 2dr HT