The nginx server block is listening on a port other than 80, if that matters. It’s all my VPN provider will allow me to forward.

server {
	listen [PORT];
	server_name mysite.i2p;

	location / {
		proxy_pass http://127.0.0.1:7657/;
		proxy_set_header Host $host;
		proxy_set_header X-Real-IP $remote_addr;
		proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
	}
}