Hello @elena_gr,

Thanks for sharing your question with the Klaviyo Community!

If you’re using the Standard Shipping Confirmation flow provided within the Flows Library and it’s not dynamically populating a tracking number or a tracking URL, this may mean these two pieces of information are not being synced from Shopify to Klaviyo as part of the Fulfilled Order metadata. You can confirm this by reviewing the metadata synced from your Fulfilled Order event either using the email preview tool or by reviewing the raw event data. 

Because you mentioned you were using a third shipping provider, I suspect this third party app may not be appropriately passing these shipping details to be synced as part of the Shopify Fulfilled Order event passed to Klaviyo accordingly. In order for the email to dynamically populate this sort of tracking information, it must be present in the Fulfilled Order event for Klaviyo to reference it. I would suggest investigate this further and taking a closer look at how this third part app connects and shares information with your Shopify data. 

Thanks for being a part of the Klaviyo Community!

David