No, you don't need glue.
Binding normally goes on before the frets are installed. Some Gibson instruments have the binding installed after the frets are in, but it makes for more work when it comes time for a refret.
Having had the opportunity to watch the Master (Frank Ford) refret a Martin at a seminar in 2000, I learned how to do a lot of things that have proved to be helpful to me. Frank used thin CA glue to wick into the fret slots after the frets were installed. You run a small amount along side the fret and immediately follow up with a quick cleanup with acetone. You literally have the CA in one hand and the acetone rag in the other. This is just a little insurance to keep things in place. He also uses a drop of CA on the ends of the frets on an unbound fingerboard. This is applied prior to the final filing and smoothing of the fret ends. I've seen folks use white glue in fret slots but I don't believe it bonds to metal. Some Stelling Banjos and Mandolins come from the factory with frets installed with epoxy. The original slots are wider then normal. The epoxy works pretty well but the cleanup of excess glue takes some time. I prefer the traditional method of installing frets.
i was trained by multiple luthiers including the top luthiers at taylor guitars and collings guitars and we all agree to use thin ca glue after the fret is in ...acetone works for clean up as well as super glue remover..both can damage the binding, just be careful...no one said fixing and building was gonna be easy..this is the stuff that takes finess and a steady hand...not to mention lots of practice
You dont need glue if your slots are correct for the tang size but if you do use it, as i do in some repairs i use a srynge left over from my dog that had diabietes , it puts a tiny drop right where you need it without a mess. Dont know what im gonna do when i run out ,had to have a prescription and a diabetic dog to get the things.
A SRYNGE IS NOT A NECESSITY I USE A TOOTH PICK AND PICK UP A DROP OF THIN SUPPER GLUE AND ITS WICKING CAPABILITIES WILL SEAP IT RIGHT WEAR IT NEEDS TO BE BEFORE I TRIM THE FRET TO THE BOARD AND IT IS HANGING OUT THE SIDE I DROP IT RIGHT ON THE FRET END BOTTOM SIDE EVEN WORKS GREAT WITH BINDING IN THE WAY THIN S/G JUST FLOWS RIGHT IN TO PLACE