Is it possible to add Numbered system to existing hex grid where every hex has lat/long number

I play tabletop games and make my own maps for these games. I find photoshop elements 2019 is very useful for this. I have produced a map that has a hex grid on it already before loading the file into photoshop for coloring/labeling etc. my question being, is there a simple way to add a numbered system to the hex grid where every individual hex has a number identifying its location on the lat and long axis? My map in question has thousands of single hexes and it would be too big a task to edit each hex individually. I have attached a .jpp that represents what i'm looking to do. Any advice would be greatly appreciated!