To install the extension:

1. Go to the Prestashop Admin panel.
2. On the left navigation bar, point the cursor to the Modules and Services.
   The menu appears as shown in the following figure:
3. Now click the Modules Manager menu, and you will come across a page like shown below.
   
4. Now you need to click on Upload a Module at the top of the page.
5. In doing so, the page opens a section shown in the image below:
6. 
7. Now in the Module File tab, choose the package file of Etsy marketplace from your system.
8. Once selected, click on the Upload this module button.
9. On the same page, scroll down and in the Modules list, search for Etsy and it will be listed on the right as shown in the image below. You have to click on the Install.