and i successfully get this done without any issue. The last line from the guide above. sudo certbot -d $DOMAIN -d $WILDCARD --manual --preferred-challenges dns certonly i used this command to get certificate.
Now i need to put this cerbot on auto renewal but aws don't have any guide on that but i found one Let's Encrypt github issue there.Github
In a comment the guy clearly state that
Certificates that are created using --manual (and without an authentication hook) cannot be automatically renewed
What command i need to run to get auto renewal for my certificate when i used manual from guide above?
You cannot auto renew any --manual method as it requires, well, manual intervention.
The github post you linked to was by a Certbot developer so is the most credible answer you can get for Certbot You can also see the certbot docs (here) which say the same.
There are ways to automate a DNS Challenge for a wildcard cert. But, I am not sure Lightsail has an API to allow that. I could be wrong but I don't think it uses, say, Route53 in the same way as EC2 for example. There are not many Lightsail experts on this forum but perhaps one will confirm or deny this.
The AWS doc you linked was for LAMP but another AWS doc for Lightsail / Bitnami for Wordpress explains how to use the bncert tool in bitnami to auto-renew certs. The drawback is it does not work for wildcard certs. A wildcard cert requires a DNS Challenge which is often harder to setup than the HTTP Challenge that can be used for non-wildcard certs. Maybe this would work for you if you don't require a wildcard.