[HttpPost]
public ActionResult<Panels> CreateNewPanel(Panels panel)
{

    _context.Panels.Add(panel);
    _context.SaveChanges();

    return CreatedAtAction(nameof(GetPanelById), new { id = panel.ID }, panel);
}

{
        "desc": "test5",
        "frame": 2,
        "aC240v": false
    }

public class Panels
    {
        public int ID { get; set; }
        public string Desc { get; set; }

        public PanelFrames Frame { get; set; }

        public bool AC240v { get; set; }

    }