how to add app key after downloading swash buckle from Nuget package manager

I downloaded swash buckle from nuget package manager and trying to add app key in swaggerConfig.cs. is that possible? If not, any other alternative way to add app key in the index.html? I could see only swaggerConfig.cs file added after installing swash buckle from nuget. Is there any other file where I could go and add the app key? Please help me I am very new to swagger and web api