db,
Yes, a power washer, or pressure washer, depending on what they call it where you live.
If you don’t have one, they can be rented.
Just use this to clean the canopy, perhaps with some detergent solution, or VERY watered down bleach/water solution.
Jim’s pressure washer idea is fine provided the Canopy has not rotted. If it is rotting any pressure to the canopy at all will cause it to tear, and then you need to replace it. A typical canopy over say a 12x12ish porch is about a grand or so (full retail)to replace installed.