Pop-up on button click

I made a pop-up contact form using Popupsmart that I would like to be opened when the “book” button for mentorships is opened. Any help on what the code could look like? I have no idea about JS.
so far I have got this on the “RFLKTers Template” or Artist page settings (see preview):

<button id="mentor-button">button</button>
<script src="https://cdn.popupsmart.com/bundle.js" data-id="803442" async defer>
(function clickMe() {
  const button = document.getElementById("mentor-button");
  button.addEventListener("click", event => {
    // window.ps.show({ id: 187784 });
    alert("button clicked");

Any help would be appreciated, thanks :slight_smile:

Here is my site Read-Only: [LINK](Webflow - RFLKT)