Hide Finish Button after clicked

-- HikaShop version -- : 3.4
-- Joomla version -- : 3.8.3
-- PHP version -- : 5.6.33

Hi
Hope you can help.
We are selling online courses using Hikashop and Joomdle.
We are currently selling voucher codes to our clients, they then give the codes to their employees which allows the employee a 100% on a course (Since the course has already been paid for by the employer).

Due to no payment being needed, Joomdle starts enrolling the person into the course/s that they have selected as soon as they click "Finish" (Which takes a few seconds to happen 2 to 10 sec depending) the problem is this people are impatient and since the system does not instantly take them to the next page, they assume it is not responding so they keep clicking finish, each time they click finish a new order is created and the system starts processing the enrollment request again, which when done enough grinds the entire website to a halt.

Is there any way to as soon as they click "Finish" hide the finish button and replace it with a message such as "Please Wait" so that they can not click it more than once.

Hi Nicolas

I will PM you with a username and password to that you can take a look.
I have taken a look at your demo site and I see what you mean, for some reason though my Hikashop looks nothing like yours, I don't have the button that disables, I don't get the product popup in the corner of the screen to show that it has been added to the cart, and my back end dashboard looks completely different.

Basically my Hikashop looks and for the most part seems to function the way it did when I started using Hikashop 2.2.2

Hi

Thank you I will gladly give up the customization to save me the frustration of duplicate orders.