More than 1 linked IP

No.

IPv4 should be the last option to use. If possible use DoH, DoT or DoQ as this are encrypted and are not constricted to your IP.

If possible use Cli, set encrypted DNS on device or use the apps provided by NextDns or some other DNS app.

Read the Knowledge Base and read the instructions on my.nextdns.io for more information.

There are also many informations on this forum and you can use the search function.

You can have more than one but you have to use a different configuration profile for each IP. 

Certainly using the other protocols is much preferred if possible.