static route with zerotier

Hello,
I have some hAP ax2 routerboards connected via a zerotier server in vpn. I should create a static route that allows me to reach a web server that resides in a VPS always passing through the zerotier interface of each routerboard and not through the eth1 port so as to always present myself to the web server with the same public IP.
Could you give me some advice because I can’t understand how to implement it and make it work.

Thanks.