How to renew Ghost blog Let's Encrypt Certificate

Connect to your ghost server via SSH and login as a ghost user.
Then following these commands:

1. Install the latest ghost-cli via npm
sudo npm i -g ghost-cli@latest

2. Renew certificate by executing the below command
ghost setup ssl-renew

3. Switch to root user
sudo su

4. Upgrade acme.sh inside letsencrypt
"/etc/letsencrypt"/acme.sh --upgrade --home "/etc/letsencrypt"

5. Renew SSL through acme.sh
"/etc/letsencrypt"/acme.sh --cron --home "/etc/letsencrypt" --debug --log