Minidlna over wireguard

There are two openwrt-routers located far apart.
Thay are connected via wireguard, so both have wg0 interface.
router1 lan is 192.168.20.1/24, and wg0 is 192.168.9.1
router2 lan is 192.168.30.1/24, and wg0 is 192.168.9.6
Both wg0 Allowed IPs are 0.0.0.0/0 and option 'Route Allowed IPs' is disabled, so routing is done by static routing. All unicasts connections work well.

minidlna is running on router2 on br-lan (lan) interface.
How can I access minidlna server on router2 from router1 lan?

I have some experience with ssdp, igmpproxy, tcpdump, wireshark and multicast, but its not enougth to configure openwrt for my purpose.

Try any and/or all of "mdns relay", "bonjour relay", "broadcast relay", "dlna relay" and any other search terms which spring to mind.