Zabbix proxy connects to Zabbix server via MikroTik

Now I want to merge two networks together using MikroTik router. At first i open zabbix tcp port 10051 so the zabbix server can listen for new information from zabbix proxy. This port also will be used for zabbix proxy to receive new item configuration:

Now i need to know exact vpn address of my mikrotik router. This will let me use the service if the external ip address has been changed:

And finally i put this vpn address into zabbix proxy configuration.
At the end my zabbix proxy configuration looks similar to this:

Server=xxxxxxxxxxxx.sn.mynetname.net
Hostname=Broceni
LogFile=/tmp/zabbix_proxy.log
DBName=/var/lib/sqlite/zabbix.db
DBUser=root
FpingLocation=/usr/bin/fping