StarTools

https://www.astrobin.com/4go7ty/?nc=user

I used the Compose module
1- Ha data in the luminance channel
2- Ha data in the red channel
3- Green was left empty
4- O-III data in the blue channel

I am new to NB processing, so I am not sure if this is the way to do it, have a look.

I'm, not sure on which filters you used (without copy pasting various bits to google search your astrobin tags)
I had thought you could have the lumanance auto created from what you have loaded collectively or is this only for RGB data, not sure just curious.
Ivo did a reply recently to a narrow band post but that was on one shot narrow band filter I think.