Compatible with the newer versions of Turtl (0.7.X), works like a charm. Not as powerful as Wallabag of course, but does the job, considering Turtl is best when using for quick and efficient way to take notes securely.
OK, after I changed client's permission to common user, and start it with common user, everything works.
~~After I successfully setup my server to use Turtl, I wonder why this add-on doesn't find my client. I am sure my client is open and connected to my server in my Manjaro (Arch-based) Linux with sudo cmd. But this add-on seems not to find it?~~
After finding out about Turtl and the browser addon which makes it very easy to use, I wouldn't be able to go without it. I only wish Turtl would automatically open on startup and require only the password - this would make it a lot easier to use.