In order to be able to track the traffic coming to your website from Pinterest and Pinterest ads, much like the Facebook pixel - you'll need to have the Pinterest tag installed on your site.
How to install the Pinterest tag
If you need tech help with this step, I highly recommend first doing a search on Youtube for:
How to install the Pinterest tag for [Wordpress, Shopify, etc...] [current year]
Example: How to install the Pinterest tag for Wordpress 2022