I couldn't use this anymore, despite I'm using the Firefox on android.
It kind of worked from the beginning, after awhile, it required me to choose something called "Cookie Jar" from the list, but the list was completely empty and I couldn't Save the edited cookie.

What happened all of the sudden? The choosing "Cookie Jar" option never popped up before and why now? I tried uninstalling it multiple times and that option still popped up.