Problem with Include JavaScript from another JavaScript in the browser

I am importing in my main JS another JS from a CDN conditionally like this:

if (('standalone' in navigator) && (!navigator.standalone)) {
  import('https://unpkg.com/pwacompat');
}

But I'd like to self-host it and include this JS file into my main JS file with JavaScript in the browser method. Like this:

pwacompact.js:

function pwacompact() {
     console.log("pwacompact");
}
export { logpwacompact };
// here goes the js I want to import...

main.js:

// ... other functions preceding the conditional import statement, and then:
if (('standalone' in navigator) && (!navigator.standalone)) {
  import { pwacompact } from "pwacompact.min.js";
logpwacompact();
}

The problem in main.js is that I want to place this import at the bottom of the script, but I can't because I get a Parse error: The import statement may only appear at the top level.

Please, how can I solve this? How can I include the second JS into the main JS and load it conditionally?

Thanks!