Not a Corel expert, but in general, for something like a stamp, you’re going to wind up with pure white text and drawings on a black background. Then the black is going to be engraved away, leaving the white parts untouched.
(I can’t open your SVG file because it wasn’t zipped first…what the forum does to files like SVGs is strip out certain descriptive information leaving a black blob out of everything…impossible to see what the original SVG file looked like.)
The easiest way though to make sure that everything happens the way you want it to with an engrave is to rasterize it, or make a Bitmap copy. (You likely know how to do that better than I do in Corel.)
Save the SVG file with the rasterized version of the engrave, and a separate cut line if you want one, and it should be good to go. It will engrave away the black, and leave the white untouched.