Can we get a "NextDNS Setup for Idiots"?

I am confused how to get NextDNS setup.

I have 3 devices in my home:

• Asus OnHub router
• Windows PC
• Android phone

How do I setup Next DNS?

For my Win and Android devices I have the NextDNS apps installed, using my Configuration ID.

Do I now also need to go into the Google Home app for the OnHub router and update my DNS settings in there to reference the IPs listed in the "IPv4 (with Linked IP)" section of 'setup', or can I leave those as either Auto or have them to Cloudflare's DNS: 1.1.1.1?