Any suggestions on creating mods for RDR2?

I have been researching but I cannot find newer content regarding creating mods in 2025.

I am trying to use scripthook but the SDK does not include files that I am trying to compile the ASI file. I wanted to create a basic side mission and add a blip etc but I cannot find those map.h files.

Is there any video or someoen I can reach out to for guidance? Thanks!

PS I have a background in creating custom zombie maps in BO3 and writing scripts!