If you don’t want to mess with another VPS you can use a global server load balancer (GSLB) provider like Akamai, Cloudflare, Azure, etc.
This being a self-host community though it’s unlikely you’d want to pursue something like this, but without knowing more about your specific use case it’s tough to make a recommendation.
If global high-availability is your primary goal then a hosted solution is probably best.
If this is just an exercise you and your friend are working on for giggles and it’s not for a mission-critical Production instance, then presumably self-hosting a load-balancer on each of your servers that includes both nodes in a target group would achieve this, though somewhat counterintuitive; if the website goes down at either location, I would imagine there’s a pretty high likelihood the LB itself would be down as well.
I’ve been testing this for years now and the transition has been seamless