return value in post method using async Task(C# And Mongodb)

Controller

// POST api/values

[HttpPost]
public void Post([FromBody]TicketsModel Value)
{

_ticketsRepository.AddTickets(new TicketsModel()

{

Source = Value.Source,
key = Value.any,
});

}

service

// add new note document
Task AddTickets(TicketsModel item);

function

// add new note document
public async Task AddTickets(TicketsModel item)
{
var data = "";

try
{
// Added Filter to Check Duplicate records on Bases of TicketId
// var query = Builders.Filter.Eq(s => s.TicketId, item.TicketId);
var results = _context.Tickets.Find(x => x.TicketId == item.TicketId).Count();

//if it is 0 then only we are going to insert document
if (results == 0)
{
await _context.Tickets.InsertOneAsync(item);
}
else
{

data = "Carname ALready Exist";
}
//return data;

}
catch (Exception ex)
{
// log or manage the exception
throw ex;
}
}