How to save contact number in flutter

with

contacts_service: 0.3.10

https://pub.dev/packages/contacts_service
Future <void> contactSave(){

    Contact contact = Contact();
    contact.givenName = 'shirsh';
    contact.displayName = 'shirsh shukla';
    contact.phones = [Item(label: "mobile", value: '9999999999')];
    contact.company = "Demo";
    ContactsService.addContact(contact);

    }