So, take a look at this; How to replace Let's Encrypt RSA 4096 bits with ECC 256 bits?
which is this URL…
https://meta.discourse.org/t/how-to-replace-lets-encrypt-rsa-4096-bits-with-ecc-256-bits/93901
What happens if the title of that thread changes? How do I have it update the link? It is cached so it doesn’t change, it seems.