want even easier?
Use the 107 edge build. there are a number of horrible issues with AGH below 107. The edge build is far more fixed. the opkg version that is openwrt is 104 and utterly useless.
theres a more recent guide that summerises the old thread.
New thread : OpenWrt AdGuard Home 101 ( DNSMASQ )
older thread : [HowTo] Running Adguard Home on OpenWrt
The new thread i added some issues regarding space and updating. I have open issues filed with AGH team they will add to 107.1.
You also dont need unbound like the poster says. you can do it all via DOH internally to AGH. I've posted a few corrections in the 2nd post.
(AGH github and documentation - https://github.com/AdguardTeam/AdGuardHome)