I wanted to share this game with some friends, without having them have to download the software. Is there a way I can make the game into a swf file from the original .aslx file? If so, I would really appreciate the help. Thank you ^^

If they play it online they don't need to download any software.

I would like to make a file compatible with browsers that I can also send without having to upload it on the site. Along with being able to play offline.

There's no way to make a Quest game into a .swf file, because there's no part of Quest that has anything to do with Flash. Some authoring systems, like Twine or Texture, export finished games as a single, stand-alone (barring multimedia) HTML file. Others, like Squiffy or Inform 7, export games as a mini-website made of several files, that you can still upload as a whole on textadventures.co.uk, itch.io or other similar services. But Quest has a significant server-side component that makes it non-trivial.

Long story short: just distribute the Quest file, so they can download and play it offline with the Windows version of the system. You get such a download link automatically if you publish your game here.