How to call an ad unit first in an HTML page?

Question

contextual advertising

Good day to all!
Please provide an answer to this question. How to make the ad code be called first in the HTML page when the site loads. I noticed that during the transition to some page of the site, the advertising code is loaded for a very long time and far from being the first. How to fix it?
VP site engine.

Answer 1

it already depends not on you, but on the cdn distributing this script.
- you can try to make the async/defer attribute for the script
- or try to use it <link rel="prefetch" href="(url)">- it has good support caniuse.com/#search=prefetch