I use gmail to check the bounce but it doesn't work

Your software
My Mautic version is:4
My PHP version is:
My Database type and version is:

Your problem
My problem is: I use Gmail to check the mail bounce but it doesn’t work, my SMTP and IMAP are both success, and I use the imap account same as SMTP account,still doesn’t work how can I fix this problem?friend
Steps I have tried to fix the problem:

do you have the cronjob setup to fetch bounced mails ?

Have you enabled gmail to allow this type of connection - I remember trying to do this a long time ago and had to go to gmail to allow a specific connection

yes,i have set fetch in cronjob like documents:
This command:php /path/to/mautic/bin/console mautic:email:fetch

also i already allow imap input on gmail,maybe you are saying other settings

well i want to know bounce rate,seems it can’t work