I am trying to prepopulate a dropdownlist for the user at a PreValue stage in Umbraco forms. This data will come from an external source (API).

I was initially thinking the you could provide data to the Settings method, but not having much luck and not sure that this is even the best approach?

public class BusinessType : FieldType
{
    [Setting("BusinessType", view = "BusinessType", prevalues = "", description = "Prepopulated Business Type Data")]
    public string BusType { get; set; } = "BusType";
    public BusinessType()
    {
        Name = "BusinessType";
        Id = new Guid("39034376-3c1a-41fa-9673-674512f9d109");
        Description = "This is an Business Type API feed";
        Icon = "icon-list";
        DataType = FieldDataType.String;
        SortOrder = 10;
    }


    public override Dictionary<string, Setting> Settings()
    {
        var settings = base.Settings();

        settings[BusType].prevalues = "One, Two, Three, Four, Five";

        return settings;
    }



    public override IEnumerable<object> ProcessSubmittedValue(Field field, IEnumerable<object> postedValues, HttpContextBase context)
    {          
        var values = new List<object>();
        var id = field.Id.ToString();
        var businessTypeName = context.Request[id + "BusinessTypeName"];
        var selection = string.Join(", ", businessTypeName);
        values.Add(selection);
        return values;
    }

}