Test email doesn't send

Less security – enabled.
OAuth 2 installed.

SMTP – connected (green pic).

When trying to send a test email:

[ Moderator note: code fixed. Please wrap code in the backtick character or use the code button. ]

Connection: opening to smtp.gmail.com:587, timeout=300, options=array ()
Connection: opened
SMTP -> get_lines(): $data is ""
SMTP -> get_lines(): $str is "220 smtp.gmail.com ESMTP g132sm17448803wme.0 - gsmtp"
SERVER -> CLIENT: 220 smtp.gmail.com ESMTP g132sm17448803wme.0 - gsmtp
CLIENT -> SERVER: EHLO regent.gracewind.nz
SMTP -> get_lines(): $data is ""
SMTP -> get_lines(): $str is "250-smtp.gmail.com at your service, [144.76.57.6]"
SMTP -> get_lines(): $data is "250-smtp.gmail.com at your service, [144.76.57.6]"
SMTP -> get_lines(): $str is "250-SIZE 35882577"
SMTP -> get_lines(): $data is "250-smtp.gmail.com at your service, [144.76.57.6]250-SIZE 35882577"
SMTP -> get_lines(): $str is "250-8BITMIME"
SMTP -> get_lines(): $data is "250-smtp.gmail.com at your service, [144.76.57.6]250-SIZE 35882577250-8BITMIME"
SMTP -> get_lines(): $str is "250-STARTTLS"
SMTP -> get_lines(): $data is "250-smtp.gmail.com at your service, [144.76.57.6]250-SIZE 35882577250-8BITMIME250-STARTTLS"
SMTP -> get_lines(): $str is "250-ENHANCEDSTATUSCODES"
SMTP -> get_lines(): $data is "250-smtp.gmail.com at your service, [144.76.57.6]250-SIZE 35882577250-8BITMIME250-STARTTLS250-ENHANCEDSTATUSCODES"
SMTP -> get_lines(): $str is "250-PIPELINING"
SMTP -> get_lines(): $data is "250-smtp.gmail.com at your service, [144.76.57.6]250-SIZE 35882577250-8BITMIME250-STARTTLS250-ENHANCEDSTATUSCODES250-PIPELINING"
SMTP -> get_lines(): $str is "250-CHUNKING"
SMTP -> get_lines(): $data is "250-smtp.gmail.com at your service, [144.76.57.6]250-SIZE 35882577250-8BITMIME250-STARTTLS250-ENHANCEDSTATUSCODES250-PIPELINING250-CHUNKING"
SMTP -> get_lines(): $str is "250 SMTPUTF8"
SERVER -> CLIENT: 250-smtp.gmail.com at your service, [144.76.57.6]250-SIZE 35882577250-8BITMIME250-STARTTLS250-ENHANCEDSTATUSCODES250-PIPELINING250-CHUNKING250 SMTPUTF8
CLIENT -> SERVER: STARTTLS
SMTP -> get_lines(): $data is ""
SMTP -> get_lines(): $str is "220 2.0.0 Ready to start TLS"
SERVER -> CLIENT: 220 2.0.0 Ready to start TLS
CLIENT -> SERVER: EHLO regent.gracewind.nz
SMTP -> get_lines(): $data is ""
SMTP -> get_lines(): $str is "250-smtp.gmail.com at your service, [144.76.57.6]"
SMTP -> get_lines(): $data is "250-smtp.gmail.com at your service, [144.76.57.6]"
SMTP -> get_lines(): $str is "250-SIZE 35882577"
SMTP -> get_lines(): $data is "250-smtp.gmail.com at your service, [144.76.57.6]250-SIZE 35882577"
SMTP -> get_lines(): $str is "250-8BITMIME"
SMTP -> get_lines(): $data is "250-smtp.gmail.com at your service, [144.76.57.6]250-SIZE 35882577250-8BITMIME"
SMTP -> get_lines(): $str is "250-AUTH LOGIN PLAIN XOAUTH2 PLAIN-CLIENTTOKEN OAUTHBEARER XOAUTH"
SMTP -> get_lines(): $data is "250-smtp.gmail.com at your service, [144.76.57.6]250-SIZE 35882577250-8BITMIME250-AUTH LOGIN PLAIN XOAUTH2 PLAIN-CLIENTTOKEN OAUTHBEARER XOAUTH"
SMTP -> get_lines(): $str is "250-ENHANCEDSTATUSCODES"
SMTP -> get_lines(): $data is "250-smtp.gmail.com at your service, [144.76.57.6]250-SIZE 35882577250-8BITMIME250-AUTH LOGIN PLAIN XOAUTH2 PLAIN-CLIENTTOKEN OAUTHBEARER XOAUTH250-ENHANCEDSTATUSCODES"
SMTP -> get_lines(): $str is "250-PIPELINING"
SMTP -> get_lines(): $data is "250-smtp.gmail.com at your service, [144.76.57.6]250-SIZE 35882577250-8BITMIME250-AUTH LOGIN PLAIN XOAUTH2 PLAIN-CLIENTTOKEN OAUTHBEARER XOAUTH250-ENHANCEDSTATUSCODES250-PIPELINING"
SMTP -> get_lines(): $str is "250-CHUNKING"
SMTP -> get_lines(): $data is "250-smtp.gmail.com at your service, [144.76.57.6]250-SIZE 35882577250-8BITMIME250-AUTH LOGIN PLAIN XOAUTH2 PLAIN-CLIENTTOKEN OAUTHBEARER XOAUTH250-ENHANCEDSTATUSCODES250-PIPELINING250-CHUNKING"
SMTP -> get_lines(): $str is "250 SMTPUTF8"
SERVER -> CLIENT: 250-smtp.gmail.com at your service, [144.76.57.6]250-SIZE 35882577250-8BITMIME250-AUTH LOGIN PLAIN XOAUTH2 PLAIN-CLIENTTOKEN OAUTHBEARER XOAUTH250-ENHANCEDSTATUSCODES250-PIPELINING250-CHUNKING250 SMTPUTF8
Auth method requested: XOAUTH2
Auth methods available on the server: LOGIN,PLAIN,XOAUTH2,PLAIN-CLIENTTOKEN,OAUTHBEARER,XOAUTH
CLIENT -> SERVER: AUTH XOAUTH2 dXNlcj1ldXJvcGVAcmVnZW50LmFjLm56AWF1dGg9QmVhcmVyIHlhMjkuQ2pIV0F2dGxkVUlHb19uUkQwOHVhVkhCSjlTQjgxM0JaTU9XSldJTDdMdFRwNk0zVnBxSU5RXzJqNkpXMUoyMkJVMWsBAQ==
SMTP -> get_lines(): $data is ""
SMTP -> get_lines(): $str is "334 eyJzdGF0dXMiOiI0MDAiLCJzY2hlbWVzIjoiQmVhcmVyIiwic2NvcGUiOiJodHRwczovL21haWwuZ29vZ2xlLmNvbS8ifQ=="
SERVER -> CLIENT: 334 eyJzdGF0dXMiOiI0MDAiLCJzY2hlbWVzIjoiQmVhcmVyIiwic2NvcGUiOiJodHRwczovL21haWwuZ29vZ2xlLmNvbS8ifQ==
SMTP ERROR: AUTH command failed: 334 eyJzdGF0dXMiOiI0MDAiLCJzY2hlbWVzIjoiQmVhcmVyIiwic2NvcGUiOiJodHRwczovL21haWwuZ29vZ2xlLmNvbS8ifQ==
SMTP Error: Could not authenticate.
CLIENT -> SERVER: QUIT
SMTP -> get_lines(): $data is ""
SMTP -> get_lines(): $str is "535-5.7.8 Username and Password not accepted. Learn more at"
SMTP -> get_lines(): $data is "535-5.7.8 Username and Password not accepted. Learn more at"
SMTP -> get_lines(): $str is "535 5.7.8 https://support.google.com/mail/answer/14257 g132sm17448803wme.0 - gsmtp"
SERVER -> CLIENT: 535-5.7.8 Username and Password not accepted. Learn more at535 5.7.8 https://support.google.com/mail/answer/14257 g132sm17448803wme.0 - gsmtp
SMTP ERROR: QUIT command failed: 535-5.7.8 Username and Password not accepted. Learn more at535 5.7.8 https://support.google.com/mail/answer/14257 g132sm17448803wme.0 - gsmtp
Connection: closed
SMTP connect() failed. https://github.com/PHPMailer/PHPMailer/wiki/Troubleshooting
Mailer Error: SMTP connect() failed. https://github.com/PHPMailer/PHPMailer/wiki/Troubleshooting

https://ww.wp.xz.cn/plugins/gmail-smtp/