Problem to sign in (MacOS Big Sur)

I have trouble signing in and using my Paperplie Word plugin on my Mac. Please see attached the screenshot. Although the Paperpile Chrome extension showed that I have signed in successfully, the Paperpile app showed that my sign-in failed.

Welcome to our forum, @Chang-Lung_Lee! Is this still the case? Have you tried restarting Word and the Paperpile plug-in, perhaps signing out of and back in to your account on Chrome? Fully uninstalling and reinstalling the plug-in would also be worth a shot. Let me know.

Yes, I have tried the steps you suggested. But the problem has not been solved.

Thanks for confirming. I have replied via email so you can share the plugin logs by that via for the team to have a look.