We have ZIp Dee today, and had Carefree on prior (Brand X) trailer, and there appear to be only two major theories of attachment to roller tubes. Attachment to trailer side is usually via rounded slot and platic/poly cord running in seam pocket at edge down length of slot. Different mfr's vay size of poly cord from 1/8" to 5/32" to 1/4", though you could buy alternate cord size at Home Depot/Lowe's kind of places.
On roller tube, options are poly cord in seam pocket down slot, or Zip Dee model involving fabric wrapped around tube and tack stitched to hold in place. If it's a slide-in model, end cap of roller tube may need removal, and I'd keep looking for better instructions to avoid loud "sproinging" sound if you release internal spring inadvertantly... [and possible serious injury!!]
Web site for Mark's RV and Awning parts shows schematics, at: https://www.marksrv.com/mark/awningfabric.htm
Finally, it appears Carter Shade was acquired by Faulkner RV Awning several years ago, so you may go upstream through sources of Faulkner awnings to see if they have specs or data on Carter Shade awnings...