Your license key unlocks automatic updates and arrives by email after purchase. Paste the key on the Settings tab. It is one key for everything: PRO is built in, so there is no separate PRO key to activate. The number of sites the key covers depends on the tier you bought. Common fixes: if a shortcode shows nothing, check that you have at least one approved testimonial and that any product or rating filter is not excluding them all. If the Wall looks unstyled, make sure the plugin is active and your theme is not stripping shortcodes. If updates do not appear, re-check the license key on Settings. The Diagnostics tab reports your environment and flags configuration problems. For anything else, the support team is one ticket away.