Hangfire for a AspNetCore website created under ServiceFabric umbrella

hi, I’m not an ASPNET developer so excuse me if I’m asking stupid things.

I’m trying to setup hangfire ina a brand new ASPNET Core site created as ServiceFabric project, the only Startup class I can find has this configuration signature:

public void Configure(IApplicationBuilder app, IHostingEnvironment env, ILoggerFactory loggerFactory)

How can i use this IApplicationBuilder (actually Microsoft.AspNetCore.Builder.IApplicationBuilder) to invoke the .Use* hangfire methods?