Install acmetool by entering the following commands in the terminal:
sudo apt update sudo apt install acmetool
automatic certificate acquisition tool for Let's Encrypt
acmetool is an easy-to-use command line tool for automatically acquiring TLS certificates from ACME (Automated Certificate Management Environment) servers such as Let's Encrypt, designed to flexibly integrate into your webserver setup to enable automatic verification. . acmetool is designed to work like make: you specify what certificates you want, and acmetool obtains certificates as necessary to satisfy those requirements. If the requirements are already satisfied, acmetool doesn't do anything when invoked. Thus, acmetool is ideally suited for use on a cron job; it will do nothing until certificates are near expiry, and then obtain new ones. . acmetool is designed to minimise the use of state and be transparent in the state that it does use. All state, including certificates, is stored in a single directory, by default /var/lib/acme. The schema for this directory is simple, comprehensible and documented.