How to add onclick event to dynamically generated HTML elements

Im trying to develop a chat app that allows for users to create a new chat room.

I already have code that runs for each item in the list, on click, will add users to the new room

Javascript:

document.querySelectorAll('.select-room').forEach(li => {
    li.onclick = () => {
        let newroom = li.innerHTML;
        if (newroom == room){
            msg = `You are already in ${room} room.`
            printSysMsg(msg);
        } else {
            leaveRoom(room);
            joinRoom(newroom);
            room = newroom;
        }
    }
});

HTML:

<nav id='sidebar'>
            <h4>ROOMS</h4>
            <ul id='room_list'>
                {% for room in rooms %}
                    <li class = 'select-room'>{{ room }}</li>
                {% endfor %}
            </ul>                
        </nav>

However, when i add new rooms, im not able to click on the list item straight away to change chat rooms, i would have to refresh the page.

Any help would be greatly appreciated