When I create a new web widget via the messaging and social menu, I can also add an alternative text in the style > launcher section.

However, this message disappears from my website if I use a custom launcher instead of a default one.

I created my custom launcher using the provided API (https://developer.zendesk.com/api-reference/widget-messaging/web/core/#open) but I don’t see in the documentation any way to add the alternative message to the custom launcher.

Currently, on my webpage, I have only the snippet to include the widget plus the javascript required to open the chat on the click:

const conversationBadge = document.querySelector('#conversation-badge');
// on page load always close widget
zE('messenger', 'close');
conversationBadge.onclick = () => {
  // open widget
  zE('messenger', 'open');
 }

what do I have to add to have the alternative text displayed as well ?