toJson method
Implementation
@override
Map<String, dynamic> toJson() => <String, dynamic>{
'id': id.toString(),
'sender_user_id': senderUserId,
'currency': currency,
'total_amount': totalAmount,
'invoice_payload': invoicePayload,
'shipping_option_id': shippingOptionId,
'order_info': orderInfo?.toJson(),
'@type': constructor,
};