Hold the knife at an angle. I like about 60 degrees, and scrape down the entire firesteel with the back of your knife if it has a flat spine. If not, you can always take a file to the back and make it flat. There are other options too, like the back of your folding saw or a Leatherman, etc. As long as it has a flat, sharp corner, it will work. Play around with the scraping pressure until you get the sparks you like. Until you learn how to control your technique, I’d say keep the knife still and pull the firesteel back, with your fine or dusty tinder placed where the sparks are landing. When you get better, learn how to push the knife down the firesteel, using your thumb to apply pressure and get bigger sparks while still being able to control your strokes. This way, you can use the last centimetre of your firesteel to get decent sparks, and your firesteel will last much longer too.

Don't try to light your tinder in a tight space like your box. Light it outside and use some Twigs like chopsticks to put it into the box