Chrome warning sync.js

I’m getting a warning from chrome in my console:

“A parser-blocking, cross site (i.e. different eTLD+1) script,, is invoked via document.write.”

Is there a specific reason this script is not run with the async tag? Like
document.write(‘<script src="‘+id+’.sync.js’ + qPString + ‘" async></’ + ‘script>’);

Hi. First of all, do you need the sync tag at all? It’s recommended only for specific use cases, such as ab testing or personalization.

As for your suggestion, that would simply switch the synchronous script to be loaded asynchronously.

Ah I understand now. Thanks!