Flame King YSN500K Heavy Duty 500,000 BTU Propane Torch Weed Burner with Flint Striker ($50). I tried this thing out on different areas with mixed results. It works well for burning little weeds out of bricks and small contained rock areas. It doesn't quite cut it for an area we have well established weeds with deep tap roots. I imagine if you burn them enough (3-5 times) they will start to die and plan to try in late summer when they are more dried out.

Better for your health, kids, pets, etc. than roundup and chemicals though. (paid link)

Amazon Link: https://amzn.to/39uECAn