What is Let’s Encrypt
To enable HTTPS on your website, you need to get a certificate (a type of file) from a Certificate Authority (CA). Let’s Encrypt is a CA. In order to get a certificate for your website’s domain from Let’s Encrypt, you have to demonstrate control over the domain. With Let’s Encrypt, you do this using software that uses the ACME protocol, which typically runs on your web host.
To figure out what method will work best for you, you will need to know whether you have shell access (also known as SSH access) to your web host. If you manage your website entirely through a control panel like cPanel, Plesk, or WordPress, there’s a good chance you don’t have shell access. You can ask your hosting provider to be sure.