If you cannot connect to your Zotero account, it probably means you did not give the read/write access rights for your library to PaperShip at login.
You need to change PaperShip access rights on Zotero platform.
- Go to http://www.zotero.org
- Log in with Zotero
- Go to https://www.zotero.org/settings/keys
- Edit the PaperShip authentication key
And finally check all the checkboxes