Congratulations, you already own a gravel bike. Drop bars and 1x gearing doesn't make it any more or less capable for gravel. A gravel bike should have: 1. clearance for wide enough tires to suit your terrain. 2. Gearing to meet your terrain. That's it.
Changing to drops has nothing to do with it. That should be a user preference decision. This will require new bars, tape, maybe a stem, brake levers, cables. Your flat bar shifters and brakes will not fit drop bars. Kind of a big switch to fit a "look" unless that's what you want.
1x gearing: Put it in the middle chain ring, pull off the front derailer, add a wider range rear cassette. Done. Or, buy a whole new 1x drive train if it's worth it. Ask yourself what you will gain besides "looks".
This is my gravel bike. Basically a 700c road bike with a second 650b wheelset, 38mm tires and wider range cassette. The 2x gearing is stock.
