Type 'Point' which is not supported by current database provider

I got the following error when I generated the code first migration.

The property 'Scheme.Polygon' is of type 'Point' which is not supported by current database provider. Either change the property CLR type or ignore the property using the '[NotMapped]' attribute or by using 'EntityTypeBuilder.Ignore' in 'OnModelCreating'.

-----------There are what I did------------

1. Startup.cs

services.AddDbContext<AppDbContext>(options => 
   options.UseNpgsql(connectionString, o => o.UseNetTopologySuite()));

1. Entity model:

using NetTopologySuite.Geometries;
public class Scheme
{
    public Point Polygon { get; set; }
}

1. DbContext:

 protected override void OnModelCreating(ModelBuilder builder)
 {
         builder.HasPostgresExtension("postgis");
         base.OnModelCreating(builder);

         builder.Entity<Scheme>(options =>
         {
             options.Property(m => m.Polygon).HasColumnType("geography");
         });
 }

1. I am using .net core 2.1, entity framework core & postgresql 10. Thanks!

[iamkinetic]

Ok, I was missing the mapping part: b.Property(m => m.Coordinates).HasColumnType("geography");

[dtkturpal]

I had the same problem, doing the following in my EntityConfiguration worked for me:

.HasColumnType("geography (polygon)");