Render Blocking Script

It is a random-post widget script. When checked with speed tool, the javascript: https://ift.tt/2n3dYXe was remarked as a render blocking JS.

I tried adding either both "asyn" and "defer" in the script. And the widget disappeared.

How do I fix this?

from JavaScript https://ift.tt/2nDfeQY
via IFTTT