command.js

import { getOutlookSignatureRawHtml } from "requests/signature";

function onMessageComposeHandler(event) {
  getOutlookSignatureRawHtml().then((response) => {
    Office.context.mailbox.item.body.setSignatureAsync(
      response.data.raw_html,
      {
        "coercionType": "html",
        "asyncContext": event
      },
      (asyncResult) => {
        asyncResult.asyncContext.completed();
      }
    );
  });
}

function getGlobal() {
  return typeof self !== "undefined"
    ? self
    : typeof window !== "undefined"
    ? window
    : typeof global !== "undefined"
    ? global
    : undefined;
}

const g = getGlobal();

Office.onReady().then(() => {
  if (Office.actions) {
    Office.actions.associate("onMessageComposeHandler", onMessageComposeHandler);
  }
});

// the add-in command functions need to be available in global scope
g.onMessageComposeHandler = onMessageComposeHandler;

Hii Sir , Any possible to click outlook calendar page click handle event trigger in outlook add-ins,