I am assuming you mean the awning fabric rather than both the fabric and metal parts.
Determine awning make and model. (Should be a sticker, often on the roller tube. Can be difficult to find.) Measure depth and width of awning.
1) measuring for rv awning fabric replacement
2) replacement rv awning fabric
Happy Camping! ///// Richard D.
2006 4x4 Ford 250 SD / 2007 Flagstaff 827 FLS
One very patient wife and one furry child who travels with us. Forty-two years of trailering and camping, and I still have a blast.