1. Log into your PrestaShop back admin.
2. Click on "Modules" on the top menu bar.
3. Search for Best Contact Form within the Advertising & Marketing category, and click on the "Install" Button.
4. Once installed, click on the "Configure" link
5. Enter the Secret Key you received from StoreYa and click on the "Save" button.
If you haven't created an account at StoreYa, go to: http://www.storeya.com/apps/best-contact-form
Create an account, customize the promotion you wish to share with your visitors (Step 1), and get the Secret Key (Step2). (Any customization of Step 1 is editable).
6. Once done you will get a successful message as seen below, and your contact form will be available on your PrestaShop store (you can edit its setting on your StoreYa account at any time).