I do not think it ever worked on Scribe. But it has been awhile since I tried it on any Kindle, I just assume it doesn't work on any of the newer firmware versions.
This is the only thread I could find here (note I am not very good at finding threads):
https://www.mobileread.com/forums/sh...ad.php?t=99229
That is how I did it before, but it is ages old, so probably does not work.