Turning on 1 LED by HTTP single command

Questions
1

I have a strip of approximately 500 RGB LEDs all working correctly.

What I’d like to do is switch one LED on with a command sent preferably via HTTP.

Is this doable using the stock WLED 0.13 version?

Macros and segments don’t seem to do what I need.

2

What about a preset with only the one LED you want?

3

You will need to look into JSON API.
Then just POST your JSON API command to WLED using HTTP.

4

This light led number 1 red

curl http://10.0.3.34/json -d {“seg”:{“i”:[1,[255,0,0]]}} -H “Content-Type: application/json”
Also {“seg”:{“i”:[1,[255,0,0]]}} in a preset does the same thing