Add menu item in bigbluebutton meeting sidebar / check https://github.com/manishkatyan/bbb-jamboard for more info

base.js

var menu = document.querySelector('div[data-test="chatButton"]').parentElement;
var sectionDiv = document.createElement("div");
var iconDiv1 = document.createElement("div");
var iconDiv2 = document.createElement("div");
var iconDiv3 = document.createElement("div");
var iconDiv3 = document.createElement("div");
var iconIcon = document.createElement("i");
var textDiv = document.createElement("div");
var textSpan = document.createElement("span");
var meetingId = document.querySelector('svg[data-test="whiteboard"]').innerHTML.match("\/bigbluebutton\/presentation\/(.*)\/.*\/.*\/svg/")[1];
// ---
sectionDiv.classList = "sc-hKUcmH sc-ijeLaK lkSQgy cwQWPD";
sectionDiv.setAttribute("role", "button");
sectionDiv.setAttribute("aria-expanded", "false");
sectionDiv.setAttribute("tabindex", "-1");
sectionDiv.setAttribute("accesskey", "P");
sectionDiv.id = "attendance-page";
sectionDiv.setAttribute("aria-label", "حضور و غیاب");
// ---
iconDiv1.classList = "sc-eSRRmr gpvuaP"
iconDiv1.onclick = function () {
    window.location = meetingId
}
// ---
iconDiv2.classList = "sc-auqbC hEKxRF"
// ---
iconDiv3.classList = "sc-jfBFGL ivWQKJ"
// ---
iconIcon.classList = "icon-bbb-group_chat"
// ---
textSpan.classList = "sc-kiowOE hsleVy";
textSpan.innerText = "حضور و غیاب"
// ---
textDiv.classList = "sc-cLqoAx iagYmL";
textDiv.setAttribute("aria-live", "off");
// ---
textDiv.appendChild(textSpan)
iconDiv3.appendChild(iconIcon)
iconDiv2.appendChild(iconDiv3)
iconDiv1.appendChild(iconDiv2)
iconDiv1.appendChild(textDiv)
sectionDiv.appendChild(iconDiv1)
menu.appendChild(sectionDiv)