How to test source on phones?

I need to test my addon on phones. So I decide to upload to Firefox addon store. However:

Content rejected by xxx about 21 hours ago

Please don’t list before it is ready for testing. Ask in support channels how to test on a phone.

Well, that makes sense. So I signed app using Web and tried on install phone. But I couldn’t find a way to install addon from xpi in firefox phone. Does anyone has idea how to test on phones?

Thanks in advance.

Sure, make sure to read these two articles:
https://extensionworkshop.com/documentation/develop/getting-started-with-web-ext/

https://extensionworkshop.com/documentation/develop/developing-extensions-for-firefox-for-android/

After you setup everything, you should be able to test your extension even without a phone - just install Android Studio with some Google Play enabled virtual phone and install Firefox there. Then you should be able to execute something like this:

web-ext run --target=firefox-android --android-device=emulator-5554 --firefox-apk=org.mozilla.firefox_beta

Regarding supported API - mostly just make sure to somehow disable all browser.windows calls, since these are not supported (because there is only one window).

List of all API is here:
https://developer.mozilla.org/en-US/docs/Mozilla/Add-ons/WebExtensions/Browser_support_for_JavaScript_APIs