Adding the payment module
There are two ways of adding PayZen payment modules:
The first method consists in adding the payment module via the Drupal_Commerce Back Office.
From the administration panel of your store, go to the Extension and click on Install a new module.
Then, click on Choose a file and upload the payment module.
The second method consists in copying the module via FTP. To do this, copy the Commerce Payzen folder into the /modules folder if your website.