How do I check if object property is true/false and output based on true/false [closed]

I’ve been trying to figure this one out – if someone has some pointers I would appriciate it. Basically I got an object which has 3 properties, I need to check if one of those properties is true or false, and return based true/false.
So far, made this code but as I understand it doesn’t recognize object.properties..

const library = [
  {
    title: "Bill Gates",
    author: "The Road Ahead",
    isRead: true
  },
  {
    title: "Steve Jobs",
    author: "Walter Isaacson",
    isRead: true
  },
  {
    title: "Mockingjay: The Final Book of The Hunger Games",
    author: "Suzanne Collins",
    isRead: false
  }
];

const showStatus = (arg) => {
  let book = arg;
  for(let i = 0;i < book.length; i++){
    if(book.isRead === true){
       console.log(`Already read ${book.title} by ${book.author}.`)
    } else {
      console.log(`You still need to read ${book.title} by ${book.author}`)
    }

  }

};

showStatus(library);