You probably could do it with epoxy but that little ridge is what gives the screen the click and holds it up.
Here is a replacement shell mini review, it has some pictures of screw locations https://gbatemp.net/threads/ds-original-phat-replacement-case-review-56k-no.364632/
You basically need to take the whole thing apart. You will need a triwing, probably a normal phillips screw, a small spanner I forget the size of (to align the bolts that pivot, you could use a small set of pliers if you wanted though)
A video showing someone pulling one apart. It is aimed at full shell replacement but it is pretty much what goes here (I would not want to try with the ribbon still there).
Assuming you are not using a DStwo/issm/iplayer then it is not a GBA emulator but actual GBA hardware.
Anyway I am seeing DSes and DS lites go for next to nothing at yard/garage sales and similar, not always but often enough. Equally if you have a bit of cash to splash around then people often bundle a DS with a bunch of games (typically craigslist and local facebook selling groups) and let it go for far less than it might go for individually so buy it and flip the games if you want. Amazon and ebay prices for screen replacements (no idea as to the quality, or indeed even if it is like some phone screens where you get third party nastiness) seem to start at around $6 if you are lucky and I have seen them go for that. Equally you don't have to be the most selective in your purchase -- you presumably have a working battery there, and possibly some other parts if you want to mix and match parts.
That said the screen could be a ribbon slipping fault (take it out and put it back in), a connector fault (various fixes, most of which are no fun) or an actual screen fault (for non TV/pricey items I tend to suggest just straight replacement). You can try taking the connector off just by removing the back case though so might as well try that first.