I have this const which is triggered by an 'onclick' button in html:

const showWebinar = (id) => {
    const yt_frame = document.getElementById("youtube_frame");
    yt_frame.setAttribute("src", `https://www.youtube.com/embed/${id}`);
    yt_frame.style.display = "unset";
    dataLayer.push({'event': `${id}`});
} 

I need it, once the button is clicked, to wait for the callback 'onReadyForServerApproval' (this callback is from the SDK found here. The HTML button looks like this:

<button class="button_click" onclick="showWebinar('YIhYCRBDOUo')">Pay</button>

where the class triggers the payment flow.

Is it possible to make 'showWebinar()' wait for the callback?

Thanks