Thanks for all your replies.
You might be wondering the purpose of this. There’s a technique for enhancing/revealing readability of indented engraving on stonework, usually a grave headstone. The usual method is to reflect strong sunlight with a mirror at an acute angle across the face of the stone, obviously the vagaries of weather, time of day, relative position of the stone come into play. Replicating the effect with a hand held torch is a non starter, at least in daylight.
I was thinking maybe the effect could be replicated using a flashgun? That unit DemiLion recommended seems ideal for this. Set the camera on a tripod facing the headstone, then take the shots from the flashgun – it would be easy to adjust the position/strength of the flash for repeated shots. That’s my theory

Am I overlooking anything?
The 200D does have centre pin hotshoe, it's replacement the 250D didn't.