web api TypeConverter does not run

I'm making my first web api and I have the following controller:

 // POST api/Recipes
    [HttpPost]
    public void Post([FromBody] RecipeModel newRecipe)
    {
        if (newRecipe != null)
        {
            using (var container = Db4oEmbedded.OpenFile(Db4oEmbedded.NewConfiguration(), DbPath))
                try
                {
                    var mayBeRecipe = (from RecipeModel recipe in container
                                       where recipe.GetHashCode() == newRecipe.GetHashCode()
                                       select recipe).FirstOrDefault();

                    if (mayBeRecipe == null)
                        container.Store(newRecipe);
                }
                catch (Exception e)
                {
                    Debug.WriteLine(e);
                }
        }

    }

To send newRecipe as a parameter I also have a type converter:

 public class RecipeTypeConverter : TypeConverter
{
    public override bool CanConvertFrom(ITypeDescriptorContext context, Type sourceType)
    {
        return true;

        //   return base.CanConvertFrom(context, sourceType);
    }

    public override object ConvertFrom(ITypeDescriptorContext context, CultureInfo culture, object value)
    {
        var newRecipe = JsonConvert.DeserializeObject<RecipeModel>(value as string);

        return newRecipe;
    }
}

The problem I have is that I try the api using Postman, sending it a RecipeModel in the body and the RecipeTypeConverter does not run (I put a breakpoint in the ConvertFrom method)

The json is the sgte:

{ "Name":"pure patata",

   "Ingredients": [
       {
           "Name":"patata"
       },
       {
           "Name":"sal"
       } 
   ],

   "Yield":4,

   "Steps":"mezclarlo todo"
}

Haber if you can lend me a hand because I've spent a lot of time investigating what happens.