I am new to Dapper. I am using Dapper in my repository class to get an object. Here is the code:

private static readonly string SELECT_BY_ =
    @"
        select 
            DI.Id,
            DI.Title as DelegateTitle,
            DI.FirstName as DelegateFirstName,
            DI.Surname as DelegateSurname,
            DI.ActivationEmail as DelegateEmail 
        from 
            PreDelegateUserInvitations as DI 
        WHERE DI.[Id] = @DelInvitationId";


public async Task<InvitationModel> GetInvitationDetails(Guid invitation)
{
    var sql = new StringBuilder(SELECT_BY_);

    if (invitation == null || invitation == Guid.Empty)
        return null;

    string sqlCmd = sql.ToString();
    
    var result = await Connection.QueryFirstOrDefaultAsync<InvitationModel>(sqlCmd,
        new
        {
            DelInvitationId = invitation
        });

    return result;
} 

When I try to execute this repository from my API with Postman request it continues to work but no error message shows. I waited a very long time to complete this but it does not show me any error message. Can anyone help me to solve the problem?

Note that, I am using SQL Server and Field type of the Id property is uniqueidentifier