Amp Error

Hi,
i try to validate my blog posts amp page but the amppproject and the amp test by Google returned me an error: “Only AMP runtime ‘script’ tags are allowed, and only in the document head”. I must replace my line of code with “<script async src=”https://cdn.ampproject.org/v0.js”></script>&#8221;.
How could i replace this line?
May i edit the plugin?
Thank you

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