A colleague approached me in 2018 to enquire about the possibility of making a ring flash for his dSLR camera, but using a UV source to excite UV reactive paints.
He had spent time researching, and had come to the conclusion that there was nothing suitable on the mass market.
A standard visible-source ring flash, a Neewer FC100 - Amazon Link - was chosen as the hardware donor.
The project involves careful dismantling of the flash head, and reverse-engineering a PCB to fit in the housing.
A suitable UV LED was chosen, and a custom PCB design created, and manufactured.