Renew certificate with no Internet


Good day.
I am doing coursework at my university. I need to install the Let’s Encrypt certificate on our RADIUS server. The problem is that the server does not have access to the Internet. Please tell me how can I get & renew the certificate of Lats Enkript without going online? I can’t use -renew comand, are there ways to get and update it manually?


The best way to do this is to use DNS validation, and perform the certificate issuance process from a different machine (that has access to the internet). You can then copy the certificate to the RADIUS server using out-of-band means (such as USB drive or whatever).

Do you have control over the DNS zone for the registered domain you want a certificate for? You need to be able to create a TXT record every time you want to create or renew a certificate.