Welcome to the forum. I have moved your post out of the support category as we can only discuss non Proofgrade material and settings in the Beyond the Manual section.
Many users have engraved on metal and specifically knife blades and posted about their experience. I suggest you use the search function and read through some or all of their posts. It will give you an idea of where to start. The main thing to know is that you are going to need a marking agent such as Cermark and that the laser dosen’t actually engrave metal.