Hello! The plan would be to trigger the `click` handler on the burger opener element.

1. The JS code would look like this:

const el = document.querySelector('.js-header__overlay-switcher');

if (el && window.app && window.app.utilities) {
  app.utilities.dispatchEvent('click', {}, el);
}

 2. Add the code above inline to `onclick` handler of your button like this:

<a href="#" onclick='event.preventDefault(); const el=document.querySelector(".js-header__overlay-switcher");el&&window.app&&window.app.utilities&&app.utilities.dispatchEvent("click",{},el);'>My Custom Button</a>