Surfacing New Fields with a Page Extension

pageextension 50100 "Customer Card Ext" extends "Customer Card"
{
    layout
    {
        addlast(General)
        {
            field("Loyalty Points"; Rec."Loyalty Points")
            {
                ApplicationArea = All;
                ToolTip = 'Points earned by this customer.';
            }
            field("Preferred Channel"; Rec."Preferred Channel")
            {
                ApplicationArea = All;
                ToolTip = 'How this customer prefers to be contacted.';
            }
        }
    }
}