Blazor TypeError

Question

Blazor application throws error whenever i try to call methods in api. I've tried different httprequest methods but nothing changed so far, still struggling to call api methods.

Error message: Unhandled exception rendering component: TypeError: Failed to fetch System.Net.Http.HttpRequestException: TypeError: Failed to fetch at System.Net.Http.BrowserHttpHandler.SendAsync(HttpRequestMessage request, CancellationToken cancellationToken) at System.Net.Http.HttpClient.SendAsyncCore(HttpRequestMessage request, HttpCompletionOption completionOption, Boolean async, Boolean emitTelemetryStartStop, CancellationToken cancellationToken) at System.Net.Http.Json.HttpClientJsonExtensions.d__91[[System.Collections.Generic.List1[[System.String, System.Private.CoreLib, Version=5.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]], System.Private.CoreLib, Version=5.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]].MoveNext() at blazor.Pages.TableDesign.OnInitializedAsync() in C:\Users\Pc\source\repos\blazor\blazor\Pages\TableDesign.razor:line 124 at Microsoft.AspNetCore.Components.ComponentBase.RunInitAndSetParametersAsync() at Microsoft.AspNetCore.Components.RenderTree.Renderer.GetErrorHandledTask(Task taskToHandle)

This is the api method which i'm trying to call:

namespace Api.Controllers{

[ApiController]
   [Route("api/[controller]/[action]")]
  [HttpGet]
       public IActionResult GetColumns()
       {
           
           SqlConnection con = new SqlConnection(connection);
           SqlDataAdapter adp = new SqlDataAdapter("select*from dynamicTable",con);
           adp.SelectCommand.CommandType = CommandType.Text;
           DataTable dt = new DataTable();
            con.Open();
           adp.Fill(dt);
           foreach (var item in dt.Columns)
           {
              colList.Add(item.ToString());
           }
           con.Close();
           return Ok(colList);

       }

Blazor http request

List<string> colNames = new List<string>
            ();
protected override async Task OnInitializedAsync() =>colNames= await Http.GetFromJsonAsync<List<string>>("https://localhost:5001/api/table/GetColumns"); ```