Local sailmaker advised me to attach slugs with bungee cord when near reefing points.... Hope that helps.
Can't quite see what's happened...
But if it is just stitching gone, sew it back again.
If the tape itself has gone, replace it with some similar weight material and restitch.
If you use the same holes as the original stitching, it won't be too difficult.
But you need a sailmaker's palm, and some needles big enough to take some heavyweight thread. You'll probably break one or two. And possibly some pliers to pull the needle through any tough bits
Traditional needle & palmI’ve had a sail slug pull off the sail - the attachment point has broken (see photo). What’s the best way to re-attach that doesn’t require a sailmaker?