The most common cause on Shopify is that the App embed is not active on the theme.
It takes just a minute to activate it from Theme Editor > App Embeds > CrazyRocket Script
(Refresh the page a couple of times to let Shopify load the new script).
You can also find a video here: https://app.screencastify.com/watch/PebVquPYvvBuovEcLJjh
Your theme might contain javascript errors (not related to our App!) that stop Shopify's asyncLoader before our main script gets loaded. As the script can't be loaded, we can't render the user interface.
These errors might be caused by Apps that left broken parts of code once uninstalled.
Check your browser's console log to see if this line of code is failing:
in such case, replace:
with
According to this post on Shopify: