I've been finding a solution to this problem for a long time.
I developed a payment method for Magento 2.2.9 and testing for the execution.
The problem comes when I try to refund the order by clicking the order button. Unfortunately, the button doesn't work. I tried to use the inspector console by the browser and it shows the missing legacy-build.min.js while the default payment method should define this js. This is the main reason why the button doesn't trigger any much. I've been looking for while why the legacy-build.min.js doesn't define and I didn't find anything.
Please share the answer if you have some clues here Note : The Legacy script will execute button to disable while i clicking it
