Thanks again.

When I do that, nothing happens because 'Apply' is still just a span.

I have a balance, which shows. I type a digit. Console shows submitFunction firing but nothing else happens.

So, what I am asking, I guess, is if there is js that is not working correctly on my installation. In which case I can track that down. Or if there is something else that I do not understand.

Code:
submitFunction, 0 arguments:               jquery.checkout_one.min.js?1604577430:5 
submitFunction, on exit submitter=null	   jquery.checkout_one.min.js?1604577430:5