Conversions Tracking but NOT revenue value

website: CatPumpsOnline.com

Using Microsofts UET tag helper extension I can see that my UET ID is coming across well, it tracks the conversions properly when the customer/user hits the “thank you” page.

But it is not able to capture the revenue value.
Here is what the Tag helper says:

Step 4 – undefined
https://catpumpsonline.com/checkout/order-received/12903/?key=xxxxxxxxxx&utm_nooverride=1

Conversion found

Website missing variable revenue code snippet

Variable revenue goals require you to add a custom code snippet to report revenue value. For Destination URL goals, this custom implementation should not contain Event parameters – Category, Action, Label, Value.

The page I need help with: [log in to see the link]