This was copied form another recent reply of mine.
You can find links to an add-on’s XPI files a couple of different ways:
- (Listed) From the public listing.
- Open the public listing for the add-on on AMO.
- Follow the “See all versions” link in the “More information” section of the page.
- The main content of this page is the version history list. Each entry will have a link to an
.xpi
file in the bottom right corner.
- (Listed and unlisted) In the Developer Hub.
- Open the Manage my Submissions page.
- In the add-on list, follow the link to the desired add-on.
- Follow the link titled “Manage Status & Versions”.
- In the version list, follow the link to version you wish to download.
- If the version was approved, you should see a link to an
.xpi
file in the “Files” section of this page.