If your tracking number is displaying as TK123, it's likely due to an incorrect setup in your Shopify menu settings.
How to Fix This in Shopify:
To resolve this issue, please follow these steps:
Go to Content > Menu
Click on the section where your tracking page is located..
Check that you have entered the code correctly, rather than the entire tracking link.
Please note that you should not add your whole tracking link, but just the last two parts of it.
And if you have modified your tracking link, make sure to upload the updated link.
For example, if you modified your tracking link to /a/tracking, then you should also upload /a/tracking instead of the default /apps/track123.
4. Click on SAVE, and refresh the page after. Wait for a minute or two for the system fully configure.
If you have followed all the steps that was provided and you still have the same error, then please reach out to our customer support.