Open your Shopify admin
Navigate to Sales Channels
and select Online Store
Click on Themes
Locate the Actions
drop-down on the page and select Edit Code
Click on theme.liquid
and delete the codes below
<script id="flashy-tracker" data-version="1.0">'use strict'; (function (a, b, c) { if (!a.flashy) { a.flashy = function () { a.flashy.event && a.flashy.event(arguments), a.flashy.queue.push(arguments) }, a.flashy.queue = []; var d = document.getElementsByTagName('script')[0], e = document.createElement(b); e.src = c, e.async = !0, d.parentNode.insertBefore(e, d) } })(window, 'script', 'https://js.flashyapp.com/thunder.js'), flashy('init', 47);</script><script id="flashy-pixels">// including everything that inside this tag.</script>
Open your Wordpress admin
Navigate to Plugins
and find WP Flashy Marketing Automation
Click on Deactivate
and then on Delete