toJson method
Implementation
Map<String, String?> toJson(String env) => {
"amount": amount == null ? null : amount,
"buyer_email": buyerEmail == null ? null : buyerEmail,
"buyer_name": buyerName == null ? null : buyerName,
"buyer_phone": buyerPhone == null ? null : buyerPhone,
"description": description == null ? null : description,
"env": env
};