How to initially create identity database tables?

I'm trying out ASP.NET Core on my Mac. I have not done much with .NET for about 6-8 years (web forms) having been working with PHP and Java EE.

Most of the projects I work on are web services/APIs for mobile applications, so I thought I'd start building a small API to help get to grips with .NET and building API's.

I've got the point where I want to integrate user authentication. I've setup a database/database context, and I've added the necessary declarations to Startup.cs;

i.e.

public void ConfigureServices(IServiceCollection services)
        {
            // Add framework services.
            services.AddMvc();

            // Database
            services.AddDbContext<DatabaseContext>(options => options.UseSqlServer(Configuration["Data:DefaultConnection:ConnectionString"]));

            // Identity
            services.AddIdentity<ApplicationUser, IdentityRole>().AddEntityFrameworkStores<DatabaseContext>().AddDefaultTokenProviders();            
        }

        // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
        public void Configure(IApplicationBuilder app, IHostingEnvironment env, ILoggerFactory loggerFactory)
        {
            loggerFactory.AddConsole(Configuration.GetSection("Logging"));
            loggerFactory.AddDebug();

            // Authentication Middleware
            //app.UseMiddleware<ClientAuthenticationMiddleware>();

            // User Authentication Middleware
            //app.UseMiddleware<UserAuthenticationMiddleware>();

            app.UseMvc();
            app.UseIdentity();
        }

I've created an ApplicationUser class with extends IdentityUser.

The next step for me is to create the necessary database tables, but can't find a definitive structure I can build or a way to do it.

I created the structure of my application using the 'yo aspnet' command and choosing the 'API/Webservice option', which by default doesn't include identity.

I'm a little confused as to how I go about creating the database structure.