Is it possible to install a SSL from Let’s Encrypt that has already been issued on Ubuntu 18.04 with Apache. I was having a lot of problems getting an SSL installed on a test site, that I guess it kept creating new ones so now it’s saying too many requests have been made and I can’t issue an SSL for my domain. Is there a way to just install/activate a Let’s Encrypt SSL that I used for the test site (same domain) on the new server/site?
Depending on the specific rate limit hit, you’ll have to wait a specific amount of time. See the documentation on the website about rate limits and see which one applies to you according to the error message you’ve received: https://letsencrypt.org/docs/rate-limits/
Also, when testing, you should use the staging environment: https://letsencrypt.org/docs/staging-environment/
If you have a valid cert in one system (TEST), it can be copied to another (PRODUCTION) system and “used” there.
The cert name won’t change, so the DNS IP should be update to use the PRODUCTION IP.
I’m not sure how much needs to be copied from the TEST /etc/letsencrypt to have the PRODUCTION system think it was originally issued there and be able to renew it going forward.