Cannot find/advertise to custom audiences created with Facebook's Tag API

I've followed Facebook's Tag API guide to create "Custom Audiences" by using "Custom Events": https://developers.facebook.com/docs/ads-for-websites/tag-api#remarketing

The final code reads:

!function(f,b,e,v,n,t,s){if(f.fbq)return;n=f.fbq=function(){n.callMethod?n.callMethod.apply(n,arguments):n.queue.push(arguments)};if(!f._fbq)f._fbq=n;n.push=n;n.loaded=!0;n.version='2.0';n.queue=[];t=b.createElement(e);t.async=!0;t.src=v;s=b.getElementsByTagName(e)[0];s.parentNode.insertBefore(t,s)}(window,document,'script','//connect.facebook.net/en_US/fbevents.js');

fbq('init', 1234567890); //Of course, I'm using my own Pixel ID ;)
fbq('track', 'PageView');

fbq('trackCustom', 'Facebook Test Audience');

The above code seems to work just fine and the custom event is being triggered (GET requests are sent and cookies "datr" + "fr" + "lu" set).

However, I cannot find "Facebook Test Audience" in the Ads Manager in order to advertise to it.

Does it take time to finally show up?

Any other ideas?

It turned out that it simply takes some time and page views for the event to show up in Facebook Ad Manager - patience is a virtue.

And voilà, I'm able now to create a new "Custom Audience", which is based upon a "Custom Combination" of my website traffic, and select the "Event" that has been triggered by my code (named "Facebook Test Audience"):

Issue "solved"!