Due to a change in Chrome done in August 2020, the default referer (misspelled intentionally) value has changed in requests.
Read about it here: https://developers.google.com/web/updates/2020/07/referrer-policy-new-chrome-default
It would be great if you could add the following in headers when doing your requests in for example in Kakao.Auth.authorize
'Referrer-Policy': 'no-referrer-when-downgrade'
Best wishes,
Martin Erlandsson