To make the site as accessible as possible, we would like to enable opening the mobile menu by focusing on the menu icon and clicking enter. At the moment only clicking with the mouse opens the menu.

Problem site: https://helsinkixrcenter.com/

Code related to opening the menu seems to be this:

jQuery(document).ready((function(e){
    e(".mobile_menu_bar").attr({role:"button","aria-expanded":"false","aria-label":"Menu",tabindex:0}),
    e(".mobile_menu_bar").on("click",(function(){e(this).hasClass("a11y-mobile-menu-open")?e(this).removeClass("a11y-mobile-menu-open").attr("aria-expanded","false"):e(this).addClass("a11y-mobile-menu-open").attr("aria-expanded","true")})),
    e(".mobile_menu_bar").keyup((function(n){13!==n.keyCode&&32!==n.keyCode||e(".mobile_menu_bar").click()})),
    e(document).keyup((function(n){27===n.keyCode&&e("#et_mobile_nav_menu .mobile_nav").hasClass("opened")&&e(".mobile_menu_bar").click()})),
    e(this).on("focusin",(function(){e("#et_mobile_nav_menu .mobile_nav").hasClass("opened")&&(e("#et_mobile_nav_menu .et_mobile_menu :focus").length||e("#et_mobile_nav_menu .mobile_menu_bar").click())}))
}));

Now, when focusing on the hamburger icon and pressing enter key - only the closing of the menu is performed, not the opening.