I have been using zerossl.com to get certs since I don’t have anything integrated on my server to do this automatically yet.
I just renewed a certificate issued a few months ago. I used the CSR and Let’s Encrypt Account Key to authenticate the new cert.
I notice this time I didn’t get a domain key (RSA Private Key) so I just used the same one from last time, and it worked.
I just wanted to clarify this point. Is one unchangeable RSA Private Key forever associated with the same CSR?