How to pass certificate in ws-federation authentication

Question

I have a question regarding WS-FEDERATION authentication. We have set it up like so

        services.AddAuthentication(sharedOptions =>
    {
        sharedOptions.DefaultScheme = CookieAuthenticationDefaults.AuthenticationScheme;
        sharedOptions.DefaultChallengeScheme = WsFederationDefaults.AuthenticationScheme;
    })
        .AddWsFederation(options =>
    {
        options.Wtrealm = Configuration["wsfed:realm"];
        options.MetadataAddress = Configuration["wsfed:metadata"];
    }).AddCookie();

But the problem is that the middlewere whose address is given MetadataAddress demands certificates for it to work. I have the certificate file, but where do I set it up?