How to fix missing key on a magic keyboard

Hello,

I have a wireless magic keyboard (the old one that require AA batteries) and one of the keys (one of the 'arrow' keys on the right side of the kayboard) fell off.

I still have the key and it is intact but I was wondering if anyone has suggestion on how I could put the key back on the keyboard using glue or something similar.

I went to an Apple Store to see what they could do about my problem but they said they could only exchange it for a replacement keyboard which would be almost as costly as the keyboard itself.

Has anyone ever successfully glued back a key on one of these magic keyboard with success?

Thanks for your help!

Regards.