Left hand tap - video

Left hand tap. By Lappe Mountain Living. 29:46 video:

https://www.youtube.com/watch?v=Z5RnJz8XU8Y

Not long ago, I hit up my local Ace Hardware for a left-hand threaded, Metric, and fine-thread nut. They could do any two out of the three, but not all of them.

Can any one suggest a source for something like that?

Try this...
{https://www.mcmaster.com/products/blind-hole-taps/system-of-measurement~metric/thread-direction~left-hand/}