Getting Error on Phone Number Click on Freshdesk UI

Hi,
I’m developing a Custom App which can be integrate with Freshdesk UI using jQuery SDK.
I have implemented the cti trigger callback on Phone Number Click. but when the user click on phone number the FDK Sdk provide an error. Please find the Screenshot .

let client;  // Use let to avoid scope conflicts and ensure proper reassignment
let email;

async function init() {
    try {
        client = await app.initialized();  // Initialize client
        const data = await client.data.get("loggedInUser");  // Await client data to prevent race conditions
        email = data.loggedInUser.contact.email;

        // Construct the iframe URL using template literals
        loadIframe(
            "miniUiIFrame",
            `https://${client.context.settings.ip}${client.context.settings.pathbase}Account/Login?username=${email}&output=embed`
        );

        client.events.on("app.activated", addEventListeners);  // Attach event listeners after initialization
    } catch (error) {
        console.error("Initialization failed:", error);
    }
}

function addEventListeners() {
    client.events.on("cti.triggerDialer", clickToCallEvent);  // Listen for CTI trigger event
}

async function clickToCallEvent(event) {
    try {
        // Use client.request for API calls instead of $.get
        const url = `https://${client.context.settings.ip}${client.context.settings.pathbase}click-2-call?user=${email}&phone_number=${event.data.number}`;
        await client.request.invoke(url);
        showNotify("info", `CLICK TO CALL EVENT TRIGGERED: ${JSON.stringify(event)}`);
    } catch (error) {
        console.error("ClickToCall failed:", error);
    }
}
function showNotify(type, message) {
    return client.interface.trigger("showNotify", {
        type: type,
        message: message,
    });
}

function loadIframe(iframeName, url) {
    const $iframe = $(`#${iframeName}`);
    $iframe.attr("src", url);
    return false;
}

init();  // Initialize the app