Under what path is the data for Firefox extensions stored?
On Android 10, Firefox 68.7.0

/data/data/org.mozilla.firefox/files/mozilla/1q4ydoub.default/extensions

I am not sure if the number before .default is specific to version or something else

For more details, see Firelord's answer here Where Firefox for Android is keeping add-on generated files?

Edit: You can paste file:///data/data/org.mozilla.firefox/files/mozilla/1q4ydoub.default/extensions in the search bar to see details of extensions, size, last modified time stamp