First you need to install a valid SSL certificate for your website and ensure it is working with https://
You have to locate the .htaccess file for your website you want to apply the redirect to.
For primary website, it will be located in the public_html folder.
Open .htaccess file using any editor and at the top of the file, copy and paste the following code:
RewriteEngine On
RewriteCond %{HTTPS} off
RewriteRule ^(.*)$ https://%{HTTP_HOST}%{REQUEST_URI} [L,R=301]
# Save .htaccess file.
Now your website will redirect from http:// they will be redirected to https:// SSL website.
Please do contact us at [email protected] if you require any further assistance.