two-way sync with google calendar

[se7en-x230]

I fail to understand how to setup the google sync.

I run calcurse-caldav --init two-way choose my account in the browser get a warning that the app is not verified I keep going get a Grant calcurse permission I allow Confirm your choices I allow It connects to 127.0.0.1 where I host a private website calcurse-caldav --init two-way --authcode .... that give me the output

Traceback (most recent call last): File "/usr/bin/calcurse-caldav", line 718, in cred = run_auth(authcode) File "/usr/bin/calcurse-caldav", line 208, in run_auth credentials = init_auth(client_id, client_secret, scope, redirect_uri, authcode) File "/usr/bin/calcurse-caldav", line 178, in init_auth credentials = oauth2_client.step2_exchange(authcode) File "/usr/lib/python3.8/site-packages/oauth2client/_helpers.py", line 133, in positional_wrapper return wrapped(*args, **kwargs) File "/usr/lib/python3.8/site-packages/oauth2client/client.py", line 2089, in step2_exchange raise FlowExchangeError(error_msg) oauth2client.client.FlowExchangeError: invalid_clientUnauthorized

[1] + 1810740 exit 1 calcurse-caldav --init two-way --authcode

someone could help me with that please?