You’re mixing terminology. Firmware is baked into the controller. You don’t install firmware onto the computer. You do, however install drivers onto the computer.
Have you connected successfully with this computer and Laser GRBL? If not, you probably need to install drivers. Search for CH341 driver. The manufacturer usually supplies a file for lightburn with configuration settings (*.lbdev). That would have been on the sd card that came with your machine. If yopu no longer have that card you might find it on the manufacturer’s web site, or possibly searching the forum someone may have uploaded one.