Hi all, I've recently been noticing that the bonsai I gifted to one of my relatives has been looking worryingly weak over the past few weeks. Neither of us know exactly what type of bonsai it is or what we can do to help it. I'd hate to have this little tree die on us, so any help would be GREATLY appreciated. Thank you!

Without leaves difficult to say, but the cause of the problem is simple:it’s inside. There is no such thing as an indoor tree.
Place it outside, give it a good shower with a garden hose or a watering can and hope that it recovers ( slim chance)
Btw: it’s not a type of bonsai, its a type of tree. Bonsai is not a species, but literally a tree in a pot