Asp.net core web api

public class HomeController : Controller
{
    private readonly DbContext _context;
    private readonly IConfiguration Configuration;

    public HomeController(DbContext context, IConfiguration configuration)
    {
        _context = context;
        //_roleManager = roleManager;
        Configuration = configuration;
    }

    [HttpPost]
    [Route("api/v1/test", Name = "Test")]
    public Task Post()
    {
        try
        {
            using (var records = new StreamReader(Request.Body, Encoding.UTF8))
            {
                ImportData(records);
                return Ok("OK"); //Error: Cannot implicitly convert type 'Microsoft.AspNetCore.Mvc.OkObjectResult' to 'System.Threading.Tasks.Task'

            }
        }
        catch (Exception ex)
        {
            return BadRequest(ex.Message); //Error: Cannot implicitly convert type 'Microsoft.AspNetCore.Mvc.BadRequestObjectResult' to 'System.Threading.Tasks.Task'

        }
    }
    public void ImportData(StreamReader records)
    {
        string connectionstring = Configuration["ConnectionStrings:dbconnstr"];

        List test = new List();

        foreach (string record in records)
        {
            Test t = new Test();
            string[] textpart = record.Split('|');
            t.ID = textpart[0];
            t.Name = textpart[1];
            test.Add(t);
        }
        var copyParameters = new[]
            {
            nameof(Test.ID),
            nameof(Test.Name),
            };
        using (var sqlCopy = new SqlBulkCopy(connectionstring))
        {
            sqlCopy.DestinationTableName = "[Test]";
            sqlCopy.BatchSize = 500;
            using (var reader = ObjectReader.Create(test, copyParameters))
            {
                sqlCopy.WriteToServer(reader);
            }
        }
    }
}