Here is a natural weed killer formula that I got from Grok. I hear it works well.

A simple and effective natural weed killer can be made using vinegar, dish soap, and optionally, salt. Here's a common formula:Ingredients:1 gallon (3.8 liters) of white vinegar (5% acetic acid or higher for best results)
1 tablespoon of liquid dish soap (preferably biodegradable, like Dawn)
Optional: 1 cup of table salt (for tougher weeds, but use cautiously as it can affect soil fertility)