Once you have enabled SSL on your site, ServerPilot makes it easy to redirect all plain HTTP requests to HTTPS.
Under your app's SSL tab, click Redirect HTTP to HTTPS after enabling SSL.
A green box will appear telling you the redirection is active.
If you need to manually redirect your entire site, create a .htaccess file in your app's public folder and add the following at the beginning of the file:
RewriteCond %{HTTP:X-Forwarded-Proto} !=https RewriteRule .* https://%{HTTP_HOST}%{REQUEST_URI} [R=302,L]
If you only want to have SSL enabled for a single directory within your app, place the .htaccess file in that directory.