Call a funcation and pass a parameter in JS

I am trying to call a function called mytask and pass index variable as a parameter. However, it seems that the compiler doesn’t recognize index.

Here is my code:

fillTask();

function fillTask() {
  tasksList.innerHTML = '';
  let index = 0;
  for (task of tasks) {
    let li = document.createElement('li');
    li.innerHTML = ' <button onclick="mytask(${index})" class="delete">Delete</button> ';
    tasksList.appendChild(li);
    //index++;
  }
}

//Delete task
function mytask(index) {
  alert("Task has been deleted");
}

When I click on the delete button I am getting this error in my console:
Uncaught SyntaxError: missing ) after argument list (at index.html:1:8)