How to download OBB files without using the Chrome/Firefox Extension?

First of all, let me emphasize that I AM NOT TRYING TO PIRATE ANYTHING.

My situation is that I have this game which needs to be updated, but I have been failing to finish the update every single time.

My guess is that the Internet connection got disrupted midway through downloading the OBB file, and Google Play app is not equipped to perform a resumable partial download.

It really gets tiresome after a while.

I tried installing the “APK Downloader Extension” but it either failed to login (on Chrome) or does nothing (on Firefox).

If there’s a way to get the URL of the OBB file, I can use Firefox’s DownThemAll, and manually transfer it to my phone.

So, to repeat the question: Is there a way to download the OBB file without using the Google Play app on the phone?