Certbot - Too Many Pending Authorisations

wondering if anyone can help me figure out how to handle this.

from the documentation I understand that I need to send the following in a POST to the server in the logs, I understand where to find all the info except how to generate the signature line. Which key do I use? how do I generate the signature to include?

POST /acme/authz/asdf HTTP/1.1
Host: example.com
Content-Type: application/jose+json

{
“protected”: base64url({
“alg”: “ES256”,
“kid”: “https://example.com/acme/acct/1”,
“nonce”: “xWCM9lGbIyCgue8di6ueWQ”,
“url”: “https://example.com/acme/authz/asdf
}),
“payload”: base64url({
“status”: “deactivated”
}),
“signature”: “srX9Ji7Le9bjszhu…WTFdtujObzMtZcx4”
}

I hope this is a simple question and I’ll smack my head when someone answers and I finally get this into my head.