As there was not such a backpack available, we decided to create one. We visited our local fire station to ask for suggestions on where to find a generic badge. He also had an outgrown appliqued fire engine shirt. We cut out the design and attached to the backpack. We used buttons to hook to the zipper.
Parental supervision is recommended.
I used one type of badge adhesive, but it washed off in the washer. Position badges and buttons on backpack until you like the layout. Iron or sew on. If desired, use the Shrinky Dink plastic and create zipper pulls or name tags. Be sure to hole punch the end before baking.