Ubiquity routers and AdGuard DNS

I can't for the life of me figure out how to get my Ubiquity router to connect to AdGuard DNS using DoH. Sure, it connects using standard DNS but that's not good.

The Ubiquity interface says that I need something called a DNS stamp and have tried to make one using the tool at https://dnscrypt.info/stamps/ but even then, my Ubiquity router won't connect using DoH.

Can someone help me? Perhaps AdGuard can officially add a DNS stamp generator for those of us using Ubiquity routers