If you're using Prestashop as a CMS, the first step is to activate the Carts Guru plugin in your Prestashop back-office.
This is done in the 'Module' section of your back-office menu.
Note: your back-office interface might be different from the one shown in the following images depending on the Prestashop version you're using.
Step 1: Modules --> Module Catalog --> Upload a module
Step 2: Drop or upload the ZIP file you exported of the Carts Guru plugin.
Step 3: Once the module is installed --> Click 'Configure'
Step 4: Click 'I have an account'
Step 5: Enter your Site ID and Auth Key
You can find this information in the Carts Guru app: Site setting section--> Integration section
Depending on which version of Prestashop you're using, the order of these integration keys may be inverted. Pay special attention to this when filling in the Site ID and Auth Key (apiToken).
If you copy/paste this information, make sure you don't accidentally include any extra spaces.
Step 6: If you entered the Site ID and Auth Key correctly, a green banner saying 'Successfully connected' will appear at the top. Go ahead and click 'Connect it now'. All done!