No operations defined in spec! asp .net core 3.1, swagger is not showing controller – Asp.net

I tried this and also this several links but not getting the answer.

this is my startup.cs file

        public void ConfigureServices(IServiceCollection services)
        {
            services.AddControllers();
            services.AddCommonService(Configuration);
            services.AddSecurityServiceRepositories();
            services.AddSwaggerService();
        }
        public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
        {
            app.UseSwaggerService();
            if (env.IsDevelopment())
            {
                app.UseDeveloperExceptionPage();
            }
            app.UseHttpsRedirection();
            app.UseRouting();
            app.UseStaticFiles();
            app.UseAuthorization();
            app.UseEndpoints(endpoints =>
            {
                endpoints.MapControllers();
            });
            //app.UseMvc();
        }

  

Adding service class, it adds the repositories

    namespace Microsoft.Extensions.DependencyInjection
    {
    public static class SecurityServiceRepositoryCollectionExtension
    {
        public static IServiceCollection AddSecurityServiceRepositories(this 
    IServiceCollection 
         services)
        {
            services.AddTransient<IUserRepository, UserRepository>();
            return services;
        }
      }
    }
 

this is my swagger class file, it adds and uses the basic swagger service

    namespace Microsoft.Extensions.DependencyInjection
    {
    public static class SwaggerServiceExtension
    {
        public static IServiceCollection AddSwaggerService(this IServiceCollection services)
        {
            services.AddSwaggerGen(options =>
            {
                options.SwaggerDoc("v1", new OpenApiInfo
                {
                    Title = "Sample API",
                    Version = "v1",
                    Description = "REST API for Sample "
                });
                options.AddSecurityDefinition("Bearer", new OpenApiSecurityScheme
                {
                    Description = @"JWT Authorization header using the Bearer scheme. rnrn 
                      Enter 'Bearer' [space] and then your token in the text input below.
                      rnrnExample: 'Bearer 12345abcdef'",
                    Name = "Authorization",
                    In = ParameterLocation.Header,
                    Type = SecuritySchemeType.ApiKey,
                    Scheme = "Bearer"
                });
                options.AddSecurityRequirement(new OpenApiSecurityRequirement()
                {
                    {
                        new OpenApiSecurityScheme
                        {
                            Reference = new OpenApiReference
                            {
                                Type = ReferenceType.SecurityScheme,
                                Id = "Bearer"
                            },
                            Scheme = "oauth2",
                            Name = "Bearer",
                            In = ParameterLocation.Header
                        },
                        new List<string>()
                    }
                });
            });
            return services;
        }
        public static IApplicationBuilder UseSwaggerService(this IApplicationBuilder app)
        {
            app.UseSwagger();
            app.UseSwaggerUI(c =>
            {
                c.SwaggerEndpoint("/swagger/v1/swagger.json", "Sample  Api V1");
            });

            return app;
        }
    }
}

   

This is my controller, I have tried the both attribute

    [Route("api/[controller]")]
    [ApiController]
    public class UserController : SecuredRepositoryController<IUserRepository>
    {
        public UserController(IUserRepository repository) : base(repository) { }

        [HttpPost("register-user")]
        // [Route("register-user")] I also tried this routing
        [AllowAnonymous]
        [ProducesResponseType(typeof(User), 200)]
        public async Task<IActionResult> AddNewUser([FromBody] User user)
        {
            try
            {
                var result = await this.Repository.RegisterUser(user);
                return Ok(result);
            }
            catch (Exception ex)
            {
                return StatusCode(500, ex.Message);
            }
        }
    }

This is coming on swagger UI instead of Controller, check the screenshot