If you have installed the Bablic Prestashop module on your Prestashop site, the SEO will be installed. Simply activate it on Bablic Settings page.
With Bablic Prestashop module, you can have your translated pages on a separate directory for each language (For example http://blog.bablic.com/fr/). This is recommended for SEO ranking.
To activate this feature, go to your Prestashop admin, and navigate to Localization -> Languages. "Add Language" to add all the languages you have in Bablic. Bablic will take care to connect all the languages in Prestashop to the languages in Bablic and to use the sub-directories in all links.