Did you know that Photoshop can export cube LUT files for you, out of the box? For over a decade now? Because if you're used to LUTs in streaming software like OBS, and you've been following tutorials that involve the OBS png file, and performing adjustments and then saving that updated PNG file and using that as LUT: you
really don't need to do this at all. Plus it'll be a tiny LUT compared to the 33 point CUBE LUT that Photoshop will happily make for you.
And if the result looks completely out of whack, the solution is usually to just flatting your image layers to a single background layer, and then regenerating the LUT.
I really wish someone had told me about this a decade ago. It's been in there basically forever.