Possible to set up a static route?

I am trying to set up a dedicated VPN router and need a static route from the Eero to the VPN router. My setup:

ISP Gateway >> Eero >> VPN Router

The VPN router is an old(er) Asus RT-AC56U that I had sitting around. I've flashed it with the latest Merlin firmware.

The problem I am running into is that when the VPN connects, there's no connection to the Internet. When I turn off VPN, everything is good. I am thinking static routes may help but maybe my problem is elsewhere?