JSFiddle - React, Tailwind, and code Playground

JavaScript

let data = [
  {
    name: "Apple",
    id: 1,
    alt: [{ name: "fruit1", description: "tbd1" }]
  },
  {
    name: "Banana",
    id: 2,
    alt: [{ name: "fruit2", description: "tbd2" }]
  },
  {
    name: "Blueberry",
    id: 3,
    alt: [{ name: "fruit3", description: "tbd3" }]
  }
];

function getKeys(obj, index) {
	console.log(Object.keys(obj[index]))
}
getKeys(data[0].alt, 0)