Q:

Authorization Bearer token not being sent in request using Swagger in Asp.Net Core

I am using Swagger to test my APIs in the Asp.Net Core application. I am sending the request using by entering the token like this Authorization: Bearer {token}. but the Authorization header is not being sent in requests.
Asp.Net Core version 3.1 and Swashbuckle.AspNetCore 5.4.1
Startup.cs Code:
public class Startup
{
    private const string _apiVersion = "v1";
    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.AddAuthentication(JwtBearerDefaults.AuthenticationScheme)
            .AddJwtBearer(options =>
            {
                options.TokenValidationParameters = new TokenValidationParameters
                {
                    ClockSkew = TimeSpan.FromMinutes(0),
                    ValidateIssuer = true,
                    ValidateAudience = true,
                    ValidateLifetime = true,
                    ValidateIssuerSigningKey = true,
                    ValidIssuer = Configuration["Jwt:Issuer"],
                    ValidAudience = Configuration["Jwt:Issuer"],
                    IssuerSigningKey = new SymmetricSecurityKey(Encoding.UTF8.GetBytes(Configuration["Jwt:Key"]))
                };
            });

        services.AddSwaggerGen(options =>
        {
            options.SwaggerDoc("v1", new OpenApiInfo
            {
                Version = "v1",
                Title = "MyProject API",
                Description = "MyProject"
            });
            options.DocInclusionPredicate((docName, description) => true);

            // Define the BearerAuth scheme that's in use
            options.AddSecurityDefinition("bearerAuth", new OpenApiSecurityScheme()
            {
                Description = "JWT Authorization header using the Bearer scheme. Example: \"Authorization: Bearer {token}\"",
                Name = "Authorization",
                In = ParameterLocation.Header,
                Type = SecuritySchemeType.ApiKey
            });
        });

    }

    // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
    public void Configure(IApplicationBuilder app, IWebHostEnvironment env, ILoggerFactory loggerFactory)
    {
        app.UseAuthentication();
        loggerFactory.AddLog4Net();

        if (env.IsDevelopment())
        {
            app.UseDeveloperExceptionPage();
        }

        app.UseRouting();

        app.UseAuthorization();

        app.UseEndpoints(endpoints =>
        {
            endpoints.MapControllers();
        });

        // Enable middleware to serve generated Swagger as a JSON endpoint
        app.UseSwagger(c => { c.RouteTemplate = "swagger/{documentName}/swagger.json"; });

        // Enable middleware to serve swagger-ui assets (HTML, JS, CSS etc.)
        app.UseSwaggerUI(options =>
        {
            // specifying the Swagger JSON endpoint.
            options.SwaggerEndpoint($"/swagger/{_apiVersion}/swagger.json", $"MyProject API {_apiVersion}");
            //options.IndexStream = () => Assembly.GetExecutingAssembly()
            //    .GetManifestResourceStream("MyProject.Web.Host.wwwroot.swagger.ui.index.html");
            options.DisplayRequestDuration(); // Controls the display of the request duration (in milliseconds) for "Try it out" requests.  
        }); // URL: /swagger
    }
}

A:

The culprit
Configuration looks fine. It seems that the auth name you defined is the possible culprit.
services.AddSwaggerGen(options =>
    {
        options.SwaggerDoc("v1", new OpenApiInfo
        {
            Version = "v1",
            Title = "MyProject API",
            Description = "MyProject"
        });
        options.DocInclusionPredicate((docName, description) => true);

        // options.AddSecurityDefinition("bearerAuth", new OpenApiSecurityScheme()
                             // "bearerAuth" -> "oauth2"
        options.AddSecurityDefinition("oauth2", new OpenApiSecurityScheme()
        {
            Description = "JWT Authorization header using the Bearer scheme. Example: \"Authorization: Bearer {token}\"",
            Name = "Authorization",
            In = ParameterLocation.Header,
            Type = SecuritySchemeType.ApiKey
        });

        // Add this filter as well.
        options.OperationFilter<SecurityRequirementsOperationFilter>();
    });

You must use the definition name as "oauth2" unless you manually pass the securitySchemaName into the constructor. As a matter of fact the SecurityRequirementsOperationFilter uses the standard name by default. Just look at the securitySchemaName's default value. 
public SecurityRequirementsOperationFilter(bool includeUnauthorizedAndForbiddenResponses = true, string securitySchemaName = "oauth2")
{
    Func<IEnumerable<AuthorizeAttribute>, IEnumerable<string>> policySelector = (IEnumerable<AuthorizeAttribute> authAttributes) => authAttributes.Where((Func<AuthorizeAttribute, bool>)((AuthorizeAttribute a) => !string.IsNullOrEmpty(a.Policy))).Select((Func<AuthorizeAttribute, string>)((AuthorizeAttribute a) => a.Policy));
    filter = new SecurityRequirementsOperationFilter<AuthorizeAttribute>(policySelector, includeUnauthorizedAndForbiddenResponses, securitySchemaName);
}

It works fine in my environment. Please try with this configuration and please don't forget to add the filter option.

