Step 01:
Login into Putty
Step 02:
Run command below:
/usr/local/cpanel/scripts/install_lets_encrypt_autossl_provider
Step 03:
Open WHM then search "Manage AutoSSL" and open it.
Step 04:
Select "Let’s Encrypt™" Check / Tick "I agree to these terms of service." and "Recreate my current registration with “Let’s Encrypt™”" then click on save button .
Step 05:
Click on Options option in menu and Check / Tick "Allow AutoSSL to replace invalid or expiring non-AutoSSL certificates." then click on Save button.
Step 05:
Click on Run AutoSSL For All Users button
Done.
Now Auto SSL will auto install as per websites requirements.