Where can I find the "nsupdate key contents"

I’m setting up Acme Let’s Encrypt on a pfsense firewall and it’s requiring ‘nsupdate key contents’.
I’m using MIAB DNS.
Any help would be greatly appreciated.

can you post the LE error message?
but to be quite honest this is probably going to be something to solve in the LE forum at: https://community.letsencrypt.org.

I’m actually in the process of setting up of acme LE and I can’t finish setting it up w/o filling in the ‘nsupdate key contents’ field. It’s required to finish.
So I don’t have an error message…yet.
I will post this on the LE forum as well.
I appreciate your input.

I honestly have no idea which methodology you are attempting. Which LE plugin are we referring to?