Problem while sending the test email

Sir,
There was a problem while sending the test email. The error debug message >

Versions:
WordPress: 4.9.8
WordPress MS: No
PHP: 7.0.30
WP Mail SMTP: 1.3.3

Params:
Mailer: gmail
Constants: No
Client ID/Secret: Yes
Auth Code: No
Access Token: No

Server:
OpenSSL: Yes
PHP.allow_url_fopen: Yes
PHP.stream_socket_client(): Yes
PHP.fsockopen(): Yes
PHP.curl_version(): Yes
Apache.mod_security: No

Debug:
Mailer: Gmail
{
“error”: {
“errors”: [
{
“domain”: “global”,
“reason”: “required”,
“message”: “Login Required”,
“locationType”: “header”,
“location”: “Authorization”
}
],
“code”: 401,
“message”: “Login Required”
}
}

The page I need help with: [log in to see the link]