1. Access the Plesk control panel.
2. Select Website & Domain from the left menu bar:

3. Click on the dropdown next to the domain:

4. Select Dashboard:

5. Click on SSL/TLS Certificate:

6. You may proceed to install the free SSL certificate.

7. From this point, you can select the options below and click on Get it free to install the SSL certificate:

8. Finally, wait for about 1 to 5 minutes to allow the system to install the SSL for your new domain. Afterward, refer to the guide below to clear your browser cache and access the website for verification:
MY client:
SG client: