Not able to connect to dynamic CRM on click of out look send button

As the new meeting is created , all the meeting details like subject, organizer and start time of meeting all these details I want to store into the Dynamic CRM table on click of the outlook(app) send button.

I have followed this link and created one launcevent.js file and on onAppointmentSendHandler function write code for connecting to CRM and store the subject and organizer into tables, also used the Office.actions.associate but still when create new meeting on click of the send button I am getting your add-in is not available try after some time, also I have used the send mode property as 'Prompt User' I am also confused where I should use onAppointmentSendHandler or onItemSendHandler. any help on this will be really appreciated as I am struggling on this for a long time.

Here is my code for connecting to CRM in launchevent.js file

Office.onReady(function () {
// Set up onItemSend event handler
Office.context.mailbox.item.addHandlerAsync(
Office.EventType.ItemSend,
onItemSendHandler
);
});

function onItemSendHandler(eventArgs)
{
// Get the meeting subject and organizer
var subject = Office.context.mailbox.item.subject;
var organizer = Office.context.mailbox.item.organizer.displayName;

// Get the access token
getAccessToken(function (accessToken) {
// Create the CRM record
createCrmRecord(subject, organizer, accessToken);
});
}

function getAccessToken(callback) {
// Configure MSAL.js
const msalConfig = {
auth: {
clientId: 'clientid',
authority: 'login.microsoftonline.com/tennatId',
},
cache: {
cacheLocation: 'localStorage',
storeAuthStateInCookie: true
}
};
const msalInstance = new msal.PublicClientApplication(msalConfig);

// Get the access token
msalInstance.acquireTokenSilent({
scopes: ['crmurl.default']
}).then(function (authResult) {
const accessToken = authResult.accessToken;
callback(accessToken);
}).catch(function (error) {
console.error(error);
});
}

function createCrmRecord(subject, organizer, accessToken) {
// TODO: Implement your code to create the CRM record using the Web API.
// For example:

var endpointUrl = "crmurl/entityname";
var payload = {
"callsubject": subject,
"name": organizer
};
var xhr = new XMLHttpRequest();
xhr.open("POST", endpointUrl);
xhr.setRequestHeader("Authorization", "Bearer " + accessToken);
xhr.setRequestHeader("Content-Type", "application/json; charset=utf-8");
xhr.setRequestHeader("OData - MaxVersion", "4.0");
xhr.setRequestHeader("OData-Version", "4.0");
xhr.setRequestHeader("Prefer", "return=representation");

xhr.onreadystatechange = function () {
if (xhr.readyState === 4) {
if (xhr.status === 204) {
console.log("Record created successfully.");
} else {
console.log("Error creating record: " + xhr.statusText);
}
}
};
xhr.send(JSON.stringify(payload));
}

if (Office.context.platform === Office.PlatformType.PC || Office.context.platform == null) {
Office.actions.associate("onAppointmentSendHandler", onItemSendHandler);
}