Requirements for template operation:
1. Create MySQL user for monitoring. For example:
CREATE USER 'zbx_monitor'@'%' IDENTIFIED BY '<password>';
GRANT REPLICATION CLIENT,PROCESS,SHOW DATABASES,SHOW VIEW ON *.* TO 'zbx_monitor'@'%';
For more information read the MYSQL documentation https://dev.mysql.com/doc/refman/8.0/en/grant.html , please. 
2. Set the user name and password in host macros ({$MYSQL.USER} and {$MYSQL.PASSWORD}).


You can discuss this template or leave feedback on our forum https://www.zabbix.com/forum/zabbix-suggestions-and-feedback/384189-discussion-thread-for-official-zabbix-template-db-mysql

Template tooling version used: 0.38