STMPAuthenticationEmail when sending email

and how to reset the password in keyrings, then I can try another one

```
Traceback (most recent call last):
File "/opt/homebrew/bin/knockknock", line 8, in
sys.exit(main())
^^^^^^
File "/opt/homebrew/lib/python3.12/site-packages/knockknock/__main__.py", line 207, in main
sender_func(**args)(run_func)()
File "/opt/homebrew/lib/python3.12/site-packages/knockknock/email_sender.py", line 53, in wrapper_sender
yag_sender.send(current_recipient, 'Training has started 🎬', contents)
File "/opt/homebrew/lib/python3.12/site-packages/yagmail/sender.py", line 156, in send
self.login()
File "/opt/homebrew/lib/python3.12/site-packages/yagmail/sender.py", line 210, in login
self._login(self.credentials)
File "/opt/homebrew/lib/python3.12/site-packages/yagmail/sender.py", line 229, in _login
self.smtp.login(self.user, password)
File "/opt/homebrew/Cellar/python@3.12/3.12.3/Frameworks/Python.framework/Versions/3.12/lib/python3.12/smtplib.py", line 750, in login
raise last_exception
File "/opt/homebrew/Cellar/python@3.12/3.12.3/Frameworks/Python.framework/Versions/3.12/lib/python3.12/smtplib.py", line 739, in login
(code, resp) = self.auth(
^^^^^^^^^^
File "/opt/homebrew/Cellar/python@3.12/3.12.3/Frameworks/Python.framework/Versions/3.12/lib/python3.12/smtplib.py", line 662, in auth
raise SMTPAuthenticationError(code, resp)
smtplib.SMTPAuthenticationError: (535, b'5.7.8 Username and Password not accepted. For more information, go to\n5.7.8 https://support.google.com/mail/?p=BadCredentials 6a1803df08f44-6ae4b417a00sm31586036d6.107 - gsmtp')
```

Read the email-sending path in knockknock/email_sender.py and the entry point in knockknock/__main__.py, then reproduce the SMTP login failure shown in the traceback. Check how credentials are passed to yagmail and whether the project documents keyring credential resets; done means the authentication failure has a confirmed, project-specific next step.

Written by the indexing model from the issue text.