Your screen shot is too small to read. The basic statement recommended in the documentation to setup the user is:
GRANT SUPER, PROCESS ON . TO ‘zabbix’@’%’ IDENTIFIED BY “s3cret”;
That will allow the zabbix user to connect from any host. If you are having problems, I would first try that, and then once it works, tailor it to meet your needs by restricting the host and permissions if need be.
If Zabbix is still not working, try to manually connect from the Zabbix server to the MySQL server you are attempting to monitor using the same credentials. That will tell you if the grants are correct or not, and if not it should give you an error message that will hopefully help diagnose the issue.