The supplier, La Cantina, is sending invoices that do not specify what the WET amount is, therefore to get the correct total it needs to be manually added after you apply the map. (screenshot included below)
You may ask then why is there a line in the extracted details called WET?? Well this is because to save you from having to add a whole new line I have extracted the invoice subtotal as the WET amount, this way makes it quicker as you just have to change the figure in it.
What do you need to do? As shown below you just need to calculate the WET amount by taking the 'Subtotal' figure $167.65 and minus from it the 'Product Cost' 129.96, then enter the amount $37.69 in the line called 'WET'. This should give the correct total.
Nice and easy :)