For those who have issues with constant login screen. All you have to do is:

1. go to Settings -> Privacy and Security
2. scroll to Cookies and Site Data
3. click Manage Exceptions
4. in field Address of website enter https://tagpacker.com
5. click button Allow
6. click button Save Changes

I guess Tagpacker should put this guide in plugin description.

This add-on does unfortunately not work with another add-on. I have to disable "Privacy Possum" on every page which I want to add a bookmark.

If I don't deactivate it, while adding a Tagpacker, the add-on window starts reloading infinitely. And on the "Privacy Possum" add-on window you can see how the numbers for "cookie" & "referer" sky rocketing within seconds.

Every Site except for the Tagpacker Homepage does not work with this add-on if you wanna keep Privacy Possum.

Screenshots:
https://droppy.lixl.nl/$/oLrev
https://droppy.lixl.nl/$/vMEET

I've been using tagpacker and the add-on for some time now. It is intuitive to use, comes with nice features (e.g., adding pictures to links, getting link recommendations etc.) and organizing by tags (instead of folders) makes organizing content very flexible. I haven't used any other bookmarking services for comparison but tagpacker provides all I need.