I have this class:

public class StatisticFormDTO
{
    public StatisticFormDTO()
    {
        FilterIds = new List<int>();
    }

    public DateTime StartDate { get; set; }
    public DateTime EndDate { get; set; }
    public IList<int> FilterIds { get; set; }
}


    [HttpPost]
    
     public async Task<IActionResult> GetStatsBySalesman([FromBody] StatisticFormDTO parameters)
     {}

and in the view

 let data = new Object();
    data.startDate = startDate;
    data.endDate = endDate;
    data.filterIds = provenanceIds;

    let json = JSON.stringify(data);

    let url = "/Dossiers/GetStatsBySalesman";

    await fetch(url, {
        method: 'POST',
        headers: {
            'Content-Type': 'application/json'
        },
        body: json
    })

I'm using asp .net 5.0 mvc, the parameter allways come null. I've did it this way many times and always works fine. I'd appretiate some help