Program.cs

public class Program
{

    using Sitecore.Feature.Hubspot.Models;
    public static void Main(string[] args)
    {
        var model = Sitecore.XConnect.Serialization.XdbModelWriter.Serialize(HubspotScoreFacetModel.Model);
        File.WriteAllText(HubspotScoreFacetModel.Model.FullName + .json, model);
    }
}