what's wrong with my code it says Cannot read property 'addEventListener' of null

const togleList = document.getElementById('toggleList'); const listDiv = document.querySelector('.list'); const descriptionInput = document.querySelector('input.description'); const descriptionP = document.querySelector('p.description'); const descriptionButton = document.querySelector('button.description'); const addItemInput = document.querySelector('input.addItemInput'); const addItemButton = document.querySelector('button.addItemButton');

togleList.addEventListener('click', () => { if (listDiv.style.display == 'none') { togleList.textContent = 'hide list'; listDiv.style.display = 'block'; }else { togleList.textContent = 'show list'; listDiv.style.display = 'none'; }

});

descriptionButton.addEventListener('click', () => { descriptionP.innerHTML = descriptionInput.value + ':'; });

addItemButton.addEventListener('click', () => { let ul = document.getElementsByTagName('ul')[0]; let li = document.createElement('li'); li.textContent = addItemInput.value; ul.appendChild(li); } );