Make sure you have this in module build script (*.build.cs)
PublicIncludePaths.AddRange(
new string[] {
"YourModuleName/Public"
}
);
PrivateIncludePaths.AddRange(
new string[] {
"YourModuleName/Private"
}
);
If you don’t know what module name is, it is folder name in Source the cs file should also be named after it