Mozilla will soon launch support for an open ecosystem of extensions on Firefox for Android. This will make Firefox the only major Android browser to support an open extension ecosystem. Developers can start preparing their desktop extensions for Android usage and discoverability on addons.mozilla.org (AMO). Mozilla expects a high demand for more extensions on Firefox for Android, so developers are encouraged to optimize their desktop extensions for mobile use. To support the transition to an Android environment, Mozilla will provide additional guides, resources, and community events. Developers should also transition their background scripts to non-persistent event pages for improved stability. They can test their mobile extensions on Firefox for Android Nightly or using web-ext for debugging and running the extension. Joining the conversation on Firefox Add-ons Discourse for support and input is also encouraged.
https://blog.mozilla.org/addons/2023/08/10/prepare-your-firefox-desktop-extension-for-the-upcoming-android-release/