I've tried but failed to connect with my zotero account. The link to zotero works, and I can log in to my zotero account. I created the key with default settings. I receive an error upon redirection to CitationGecko, which varies depending on my browser:
Firefox: "Secure Connection Failed"
Edge: "Couldn't obtain valid access token from Zotero."
Chrome: "Couldn't obtain valid access token from Zotero."
If I return to zotero, it appears that each attempt creates a key.
I'm on Windows 10, using a free zotero account.
Thanks for your help!