Warning: Unknown MySQL server host

When i enter in plugin–> xcloner appear this:

Warning: mysqli::mysqli(): (HY000/2005): Unknown MySQL server host ‘[SERVERHOST]’ (1) in /…/wp-content/plugins/xcloner-backup-and-restore/common.php on line 64
Connect failed: Unknown MySQL server host ‘[SERVERHOST]’

-> Where [SERVERHOST] is the number of the host<-

Can someone help me? thanks

https://ww.wp.xz.cn/plugins/xcloner-backup-and-restore/