Click on the ROCKET ICON on the top right corner of your AstroBox Settings.
That will connect you to the cloud.
Once it worked, it will be GREEN.
All icons (like the screenshot above) on the top right should be GREEN.
Then, you’ll be able to access your printer/Astrobox from the cloud.
…or are you saying that you have already tried this?
500 is Internal Server error.
…if I were to guess, that’s either temporary or is not a real problem because the cloud works fine for me.
Just for kicks, can you also try all of this with an INCOGNITO browser with any firewalls etc. Turned off to rule out a interference on your end?