Ionic contacts plugin returning plugin_not_installed error

Appflow
1

This code below is in my provider directory and is supposed to return an array of contacts

import { Injectable } from '@angular/core';
import { NavController } from 'ionic-angular';
import {Contacts, Contact, ContactField, ContactAddress, ContactName, ContactFindOptions} from '@ionic-native/contacts';

getAllContacts() {
    return this.contacts.find(
      ["displayName", "phoneNumbers"],
      {multiple: true, hasPhoneNumber: true}
    )
  	.then((contacts) => {
      for (var i=0 ; i < contacts.length; i++){
        if(contacts[i].displayName !== null) {
          var contact = {};
          contact["name"]   = contacts[i].displayName;
          contact["number"] = contacts[i].phoneNumbers[0].value;
          this.contactList.push(contact);
        }
      }
      return this.contactList;
		});
  }