unauthorized_client

I have an issue with the example on this page:
https://github.com/authlib/example-oauth2-server

curl -u zdIKyq4ngefIcRtcU83mYK4x:oBxXfYNeqGtBq07UHrmMXLfonxTimxoJ0qpIhV9lQWYtN82Z -XPOST http://127.0.0.1:5000/oauth/token -F grant_type=password -F username=test1 -F password=valid -F scope=profile

Response: {"error": "unauthorized_client"}
There is not enough debug to let me know what the issue is. The username is test1, correct.

From http://127.0.0.1:5000/
(copied from HTML)

Logged in as test1 (Log Out)
Client Info
client_id: zdIKyq4ngefIcRtcU83mYK4x
client_secret: oBxXfYNeqGtBq07UHrmMXLfonxTimxoJ0qpIhV9lQWYtN82Z
client_id_issued_at: 1637592243
client_secret_expires_at: 0
Client Metadata
client_name: test
client_uri: https:/authlib.org
grant_types: ['authorization_code, password']
redirect_uris: ['https://authlib.org']
response_types: ['code']
scope: profile
token_endpoint_auth_method: client_secret_basic