Trick with Resistol : this first trick is very useful for repairing the inside of the bag. Apply a little glue under the material to be reattached and let it dry. Color the surface with eyeliner the same color as the bag.
At this point apply a second layer of glue and leave to dry for 20 minutes . If you notice that the treated area is lighter than the rest of the fabric, don’t worry because it will return to its original color when it dries.