How to add a subdomain to an existing LetsEncrypt certificate via ACME?

Question

linux

Given: The Let`s Encrypt certificate for the www.example.com domain is created and updated by the excellent acme.sh utility. The site is running on a server running Apache.
Question: How can I add example.com ahead of time (manually) to an existing certificate ?
With the same webroot dir. I read the acme documentation, apparently badly :(
ACME has been updated to the latest version.

Answer 1

Suddenly it will come in handy for someone:
Everything!

Answer 2

Question: How can I add example.com ahead of time (manually) to an existing certificate?

No way. The certificate is issued for the domain. It will be different for two domains.

Answer 3

And why didn’t you like the example with the readme on github?
Example 2: Multiple domains in the same cert.

acme.sh --issue -d example.com -d www.example.com -d cp.example.com -w /home/wwwroot/example.com

Answer 4

You cannot change information in an existing certificate . If any changes are made to the certificate, it will be reissued.