My wild guess is that if the authorization had included a domain name that was authorized with TLS-ALPN-01, then during their recent incident they needed to revoke the existing authorization. (Or maybe it got revoked somehow even without using TLS-ALPN-01?)
In any event, I'm guessing the main thing you'd need to do is just to no longer use that authorization but make a new one. But it'd be hard to describe you'd do that in your custom integration without more details. Probably it should automatically make a new one if it discovers that the authorization is revoked.