Allow local DNS Server for a certain domain or network

My router does DHCP and DNS for all leases it grants.

When i use nextdns my local router gets ignored as a DNS and nextnds blocks those responses.

How can i configure nextdns to delegate a certain network or domain (foobar.localnetwork)?

I am a aware that i could use Rewrites per Host/IP and i know how to solve it on the client side but i want to solve it within nextnds.

Thank you!