select element that is created by insertAdjacentHTML for adding or remove class

guys i want to add one class to li Element aftet it is created through insertAdjacentHTML but i dont know how i can select it in fact i replaced insertAdjacentHTML way with append that i commented appen way; my codes are:

function todosGenerator(todosList) {
todoListElem.innerHTML = ''

    // let newTodoLiElem, newTodoLabalElem, newTodoCompleteBtn, newTodoDeleteBtn


    todosList.forEach(function (todo) {
    //     console.log(todo);
    //     newTodoLiElem = $.createElement('li')
    //     newTodoLiElem.className = 'completed well'

    //     newTodoLabalElem = $.createElement('label')
    //     newTodoLabalElem.innerHTML = todo.title

    //     newTodoCompleteBtn = $.createElement('button')
    //     newTodoCompleteBtn.className = 'btn btn-success'
    //     newTodoCompleteBtn.innerHTML = 'Complete'
    //     newTodoCompleteBtn.setAttribute('onclick', 'editTodo(' + todo.id + ')')

    //     newTodoDeleteBtn = $.createElement('button')
    //     newTodoDeleteBtn.className = 'btn btn-danger'
    //     newTodoDeleteBtn.innerHTML = 'Delete'
    //     newTodoDeleteBtn.setAttribute('onclick', 'removeTodo(' + todo.id + ')')

        // if (todo.complete) {
        //     newTodoLiElem.className = 'uncompleted well'
        //     newTodoCompleteBtn.innerHTML = 'UnComplete'
        // } **/! ican not write these lines with insertAdjacentHTML**

        // newTodoLiElem.append(newTodoLabalElem, newTodoCompleteBtn, newTodoDeleteBtn)

        // todoListElem.append(newTodoLiElem)



        todoListElem.insertAdjacentHTML('beforeend','<li class="completed well is"><label>'+todo.title+'</label><button class="btn btn-success" onclick="editTodo('+todo.id+')">Complete</button><button class="btn btn-danger" onclick="removeTodo('+todo.id+')">Delete</button></li>')

    

    })
    
}

I think your commented code is better, but if you want to stick with the insertAdjacentHTML, you can alter to something like this:

    var liClass, cBtnInner;
    if (todo.complete) {
        liClass = 'uncompleted well';
        cBtnInner = 'UnComplete';
    } else {
        liClass = 'completed well is';
        cBtnInner = 'Complete';
    }
    todoListElem.insertAdjacentHTML(
        'beforeend', 
        '<li class="' + liClass + '"><label>' + todo.title + 
            '</label><button class="btn btn-success" onclick="editTodo(' + 
            todo.id + ')">' + cBtnInner + 
            '</button><button class="btn btn-danger" onclick="removeTodo(' + 
            todo.id + ')">Delete</button></li>'
    );