DHCP Forwarder

i compiled today a OpenWRT for Banana Pi R2

Everything works well. I'ld like to configure a DHCP Relay Service, because my DHCP Servers are in a separate VLAN.

I compiled the image with isc-dhcp-relay-v4. But there were no config files
I found a DHCP Server odhcpd. But i dont know how to configure with DHCP Relay for IPv4.

What is a good DHCP Relay Agent for OPENWRT 19.07 and where is a documentation?

Than you in advice and best regards