SQL SERVER data source venet handler

Sience this application is presented as a low code app., please advise me why when I tried to create an "on click event" i get the error
"dotnet: Pages\AddExportInboundCommand.razor.designer.cs(161,21): error CS0246: The type or namespace name 'UspInboundExportCalculation' could not be found (are you missing a using directive or an assembly reference?) [D:\MyProjects\test\server\BcrsfWebApp.csproj]"
Where should I set the directive or the assembly reference?

I'm not sure I understand what exactly you are doing however you might need to use UspInboundExportCalculation type with full name including namespace. Check where this type is declared.

Hello Enchev
I have a store procedure in data base. This was translated by Radzen like in the picture below. I want to acces this method by clicking a button. Can you tell me whar fields to chose from the event handler( none of the information from the documentation is suitable. I get errors like "could not be found (are you missing a using directive or an assembly reference?) "

I want that store procedure to be executed by clicking a button

What is this type then? The stored procedure from your screenshot does not return such value.

It does, this is the whole code
public async Task UspInboundExportCalculations(string ExportInboundCommandid)
{
OnUspInboundExportCalculationsDefaultParams(ref ExportInboundCommandid);

      SqlParameter[] @params =
      {
          new SqlParameter("@returnVal", SqlDbType.Int) {Direction = ParameterDirection.Output},
          new SqlParameter("@ExportInboundCommandid", SqlDbType.UniqueIdentifier) { Direction = ParameterDirection.Input, Value = new Guid(ExportInboundCommandid)},
      };
      context.Database.ExecuteSqlRaw("EXEC @returnVal=[WebApp].[usp_InboundExportCalculation] @ExportInboundCommandid", @params);

      int result = Convert.ToInt32(@params[0].Value);

      OnUspInboundExportCalculationsInvoke(ref result);

      return await Task.FromResult(result);
  }

Again, this procedure returns an int value if the execution is successful or not

This is the procedure method name

Ok, but how can I invoke it and what should I put to Then event?

This procedure does not return any value that can be used by Then action of the event. You can just execute it.

So I chose Execute C#
and at code what should I write?

By execute I mean Invoke Data Source Method action not Execute action.

Just like this?
Without Then?