La matriz de libros se mapea y se inserta en el html. Pero el error dice que deleteThisBook() no está definido
function loadData(){ var output = document.querySelector(".output") output.innerHTML = `${books .map(function (book){ return ` <ul class="list-group list-group-flush"> <li class="list-group-item"><b>Title</b>: ${book.title}</li> <button onclick="deleteThisBook(this, ${book.title})">Delete</button> </ul>` }).join("")}`; } function deleteThisBook(delButton, t){ console.log("clicked") } loadData();