Add the function of installing extensions from other chrome.addon and opera.addon storages to the Firefox browser or simply fix the extension by default as in the Brave browser and this is the converter/compiler extension, and here is its name Chrome Store Foxified - https://addons.mozilla.org/ru/firefox/addon/chrome-store-foxified/, details about this function on: https://www.comss.ru/page.php?id=3118
To be honest, I came up with even earlier than the "underdeveloped" Opera browser, which was still little functional before the update and before the "birth" of the regional browser, the function of installing extensions from stores, chrome.google.com/webstore/detail/ and addons.opera.com addons.mozilla.org.