For learning purposes I am creating a Todo app in JavaScript. I have a function that takes the input value(Task) and push it to an array of objects.

I want to be able to remove the object task out of the array listOfTask when button delete is clicked and I want to switch the completed property of task to true when button completed is clicked. My problem is that the user can click randomly any object in the array. So I can not link the event click to the object that I want to manipulate using index. Any ideas on how to achieve this will be highly appreciated. By the way, this is my fisrt time posting a question so please let me know if my question needs improvment or clarification.

let listofTask=[];
function addTask(){
 let taskAdded= document.getElementById('input1').value;

 let task=new Object;
 task.task=taskAdded;
 task.completed=false;

 listOfTask.push(task);
 appendTask(listOfTask);
   
}

So the function appendTask() craetes two buttons per each task and print them into the HTML

function appendTask(array){
    
    if(array.length>0){
        
        let div=document.getElementById('show-tasks');
        
        let ul= document.createElement('ul');
        
        let completedButton= document.createElement('input');
        completedButton.value= 'Completed';
        completedButton.type='button';
        completedButton.onclick=function completedTask(){
            this.parentNode.classList.add("mark-completed");
        }
        
        let deleteButton= document.createElement('input');
        deleteButton.value='Delete';
        deleteButton.type='button';
        
        deleteButton.onclick= function deleteTask(){
            this.parentNode.remove();
        }

        ul.innerHTML=ul.innerHTML+`<li>${array[array.length-1].task}</li>
                                     `;

        ul.appendChild(completedButton);
        ul.appendChild(deleteButton);
        div.appendChild(ul)
        

    
}
}

At this point I am able to succesfully mark a task as completed and remove it from the HTML but I want to be able to manipulate the objects inside the array as well. Thank you!