cant include

cant include groomcomponent in my c++ file. i also have hairstrandscore and when im adding niagara its sayes module could not be loaded

You need to include the header

#include "GroomComponent.h" 

and module HairStrandsCore in your .build file in the section

.....
PublicDependencyModuleNames.AddRange(new string[] { "Core", "CoreUObject", "Engine", "InputCore", "HeadMountedDisplay", "EnhancedInput", "HairStrandsCore" });

i have both of them

Ok so you need the prerequisite of the module “Niagara” so add it before “HairStrandsCore”

.....
PublicDependencyModuleNames.AddRange(new string[] { "Core", "CoreUObject", "Engine", "InputCore", "HeadMountedDisplay", "EnhancedInput", "Niagara", "HairStrandsCore" });

Then #include “GroomComponent.h” compiles correctly