Can I add a second IdentityServer4 to my WebApi Authentication pipeline?

Question

I have an WebApi (DemoService). I protect it with the IdentityServer4. If I request the Api with a Bearer token my DemoService makes some requests to be sure that I am allowed to access the DemoService.

1. GET http://192.168.178.20:5200/.well-known/openid-configuration
2. GET http://192.168.178.20:5200/.well-known/openid-configuration/jwks

In the default scenario my DemoService authorizes against only one IdentityServer4 and everthing works well. Is it possible to make the URL (192.168.178.20:5200) of the IdentityServer4 flexible, to authorize against a second IdentityServer4? Or is it possible to add a Second IdentityServer4.

Here is my Startup.cs:

namespace DemoService
{
    public class Startup
    {
        public Startup(IConfiguration configuration)
        {
            Configuration = configuration;
        }

        public IConfiguration Configuration { get; }

        // This method gets called by the runtime. Use this method to add services to the container.
        public void ConfigureServices(IServiceCollection services)
        {
            services.AddMvcCore()
                .AddAuthorization()
                .AddJsonFormatters();

            services.AddAuthentication("Bearer")
                .AddIdentityServerAuthentication(options =>
                {
                    // can I decide in the current
                    // Request which Authority to use?
                    // I want to switch the url between two
                    // IdentityServers
                    options.Authority ="http://192.168.178.20:5200"; 
                    options.RequireHttpsMetadata = false;

                    options.ApiName = "DemoService";
                });

            //// If I try to add a second IdentityServer I
            //// get the following failure:
            //// System.InvalidOperationException: 'Scheme already exists: BearerIdentityServerAuthenticationJwt'
            // services.AddAuthentication("Bearer")
            //     .AddIdentityServerAuthentication(options =>
            //     {
            //         options.Authority ="http://localhost:5000"; 
            //         options.RequireHttpsMetadata = false;
            //         options.ApiName = "DemoService";
            //     });


        }

        // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
        public void Configure(IApplicationBuilder app, IHostingEnvironment env)
        {
            if (env.IsDevelopment())
            {
                app.UseDeveloperExceptionPage();
            }

            app.UseAuthentication();

            app.UseMvc();
        }
    }
}