How to add custom header in swagger operation

I am currently developing a .net core web API that will use a swagger as its documentation. 

Everything was perfect, except almost of the request method has a required data that was in the header. 

My problem was how to add an input header in the Swagger UI. After a few research, I found it. Here's how to do it.

1. Create a filter class that implement IOperationFilter

   
   
     public class MyCustomHeaderFilter : IOperationFilter
       {
           public void Apply(OpenApiOperation operation, OperationFilterContext context)
           {
               if (operation.Parameters != null)
               {
                   operation.Parameters.Add(new OpenApiParameter
                   {
                       Name = "FilterName",
                       In = ParameterLocation.Header,
                       Description = "access token",
                       Required = false,
                   });
               }
   
           }
       }
   
   

2. Register the class in swagger using OperationFilter

          
       swagger.OperationFilter<TenantCodeOperationHeader>();