So that sounds like you were trying to just create a 3D laser file yourself. That’s not how this works. So the basic Trick is you need a file properly made so the automagical 3D algorithm will do this. So the algorithm uses grayscale to decide how hard to burn. So as a simple example put white text on a black background and the black is full-burn while the white is no-burn so that would be a simple embossed text. You could be more “3D’ish” if you then put a feather outline on the text (say a gradient glow) and then the laser would vary the power into a nice fillet around the text. But you’re presumably wanting something fancier, but the above is critical to understand what it’s doing before getting fancy.
So now you have your 3D model ready, and it’s time to convert it to a 3D model. In this project I link to a tutorial on how to generate it. (It took a bunch of fiddling, so be patient, and the Mac version of blender didn’t quite match the screens in the tutorial, but eventually I got everything to work). But basically I used blender to render a 3D depth map file (as a PNG) of my 3D model.