<!--
It is impossible to access a JavaScript variable using
HTML. HTML is completely different to JavaScript, it is
a markup language (HTML stands for Hyper Text Markup
Language), meaning it is only used to format or prepare
base content that is displayed.
You could access a global variable from an external
script, however, using an in-line script tag in HTML.
-->
<script src="some_external_script.js" defer></script>
<script defer>
// if a global variable named some_global_variable
// was defined by 'some_external_script', it can
// be accessed here
console.log(some_global_variable);
</script>