Will NOT authorise

I am also having a problem setting Postie up. I have triple-checked my settings in Postie (and gmail) but when I do a config test, this is what I get:

Warning: imap_open(): Couldn’t open stream {imap.gmail.com:993/service=imap/ssl/notls/novalidate-cert}INBOX in /home4/miranda8/public_html/xxxxxx/wp-content/plugins/postie/postieIMAP.php on line 89
imap_open failed: Can not authenticate to IMAP server: [ALERT] Please log in via your web browser: https://support.google.com/mail/acco
Unable to connect. The server said:

I’ve checked with hostgator and they said that port 993 is not blocked by them. I’m completely frazzled out with this …help please!!

https://ww.wp.xz.cn/plugins/postie/