Why I am unable to populate and select the custom item in juery-ui autocomplete?

const data = [{
    user_id: 18,
    email: "gmail@chucknorris.com",
    phone: null,
    fullname: "Chuck Norris",
    total_points: 0,
    reservations: 1,
    active: true,
    referer: "Direct"
  },
  {
    user_id: 19,
    email: "billgates@microsoft.com",
    phone: null,
    fullname: "Bill Gates",
    total_points: 0,
    reservations: 1,
    active: true,
    referer: "Direct"
  },