Adwords Remarketing code

[ibadat]

Hi there,

I'm trying to complete my Adwords tag by adding the global site tag and event snippet to my shopify store. I'm struggling to identify what I need to replace the values within my event snippet seen here (this is what I was given via Adwords) - 

<script> gtag('event', 'page_view', { 'send_to': 'AW-XXXXXX', 'ecomm_pagetype': 'replace with value', 'ecomm_prodid': 'replace with value', 'user_id': 'replace with value' }); </script>  

Can anyone explain how I find the values for the following...

1. ecomm_pagetype
2. ecomm_prodid
3. user_id

Thank you in advance