This kind of old, so you probably solved it already.

@first: OpenAPI Specification and Swagger tools are for HTTP-based APIs only and do not support other protocols like FTP.

• Create a class with a byte array,

     [OpenApiExample(typeof(ModuleUploadExample))]
     public class ModuleUpload
     {
         public byte[] zip { get; set; }
  
     }
  
  

• ·         Create an example

      internal class ModuleUploadExample : OpenApiExample<ModuleUpload>
      {
          public override IOpenApiExample<ModuleUpload> Build(NamingStrategy namingStrategy = null)
          {
              this.Examples.Add(
                     OpenApiExampleResolver.Resolve(
                         "ParametersExample",
                         new ModuleUpload()
                         {
                            zip = new byte[] { 1, 2, 3, 4 }
                         },
                         namingStrategy
                     )); ;
  
              return this;
          }
      }
  }
  
  

• ·         Should get you something like this

  enter image description here