Add All Google Contacts with a Phone Number to a Label

code.gs

var nameOfLabel = "Contacts With a Phone Number";

function run() {
  
  var label = ContactsApp.getContactGroup(nameOfLabel);
  if (!label) {
    label = ContactsApp.createContactGroup(nameOfLabel);
  }
  
  var allContacts = ContactsApp.getContacts();
  Logger.log("Searching " + allContacts.length + " contacts...");
  for (var i in allContacts) {
    var phones = allContacts[i].getPhones();
    if (phones.length) {
      Logger.log("Adding " + allContacts[i].getFullName() + "...");
      label.addContact(allContacts[i]);
    }
  }
  
}