Help with opkg -f

[balanga]

I'm trying to work out how to use opkg -f if openwrt is not the default repository.

I'm trying to find what sets the default repository.

This post shows more or less what I'm looking for:

Add repository for opkg

in the official openwrt repo there is adguardhome however i run the @davidc502 builds and its opkg is configured differently is there a way i can add the official repository so i can download this package? [opkg]