Step 1: Login to the Plesk control panel with your login credentials.
Step 2: Click the Websites and Domains section.
Step 3: Then select the domain for which you are going to generate the Let’s Encrypt SSL.
Step 4: To generate the Let’s Encrypt certificate, click the Let’s Encrypt option.
Step 5: Provide a valid email address in the ‘Email Address’ section. For providing the certificate for the domain with www extention select the ‘Include www.example.com as an alternative domain name’ check box.
Step 6: Click ‘Install’ to install the SSL certificate.
Step 7: Then, in the ‘Websites and Domains’ section, click the Hosting Settings under the domain.
Step 8: In the Security section, select the ‘SSL support’ check box, then select the Let’s Encrypt certificate under the Certificate.
Step 9: Now the SSL certificate has been successfully installed for your domain.