Worth mentioning, if you're going for a cheapy, don't expect for it to live up to its specs.
I got one of those ~$10 USD 365nm "5W" flashlights, this one
https://www.ebay.com/itm/NEW-1-2PCS-High-Powered-UV-Lamp-Black-Light-Ultra-Violet-Flashlight-365nm-5W-LED/303349748350 , that lived up to none of its claims. Even on the brighter setting it's a pretty dim illumination, and not because my eyes can't see it... it measures like 394nm on the spectrometer so it's clearly not the LED binning they're claiming either. It's also clear from the kinds of things that fluoresce that it's not a short wavelength of UV.
Haven't actually used it for curing, but I got it with the intent to use it on some of the curable solder mask you can get, it will probably do the job, just with longer cure times than you'd hope for.