Adguard home dns setup

I’ve installed adguard home on GL-MT1300.
Can you please let me know the steps in enabling DNS filtering?

Do I need to setup the dns filtering in adguard home-> DNS settings first? then setup it up in router admin-> Custom DNS Server? thanks in advance.

Yes.

NO. Do not set any customied DNS servers. As Adguard Home need to take control

Thanks.
can someone help me with details steps with adguard home-> DNS settings?

How about just use the default settings.