Gift Coupon, is this setup Correct?

-- HikaShop version -- : 4.3.0
-- HikaSerial version -- : 3.1.2
-- Joomla version -- : 3.9.23

Hello,
I'm trying to convert a 'product' my client currently sells manually on his website. He has a product setup as a gift voucher for £5.

Currently, this is more of a manual process, when an order is confirmed, he manually then emails a coupon code to the customer.

We now want to automate this so when an order is confirmed for a gift coupon then the customer automatically receives the discount code.

I have installed HikaSerial, and tried following the documentation to set up what I believe is the correct process. Attached are my screenshots, are these correct? Will a customer now receive an email with the code attached? I did not see or understand how to set the value for the coupon discount, I saw a percentage field on the plugin but not a set price. Where can I set this?

Thanks
Lee

Jerome,
Thanks for the reply, I have hopefully followed your instructions. I've attached two more screenshots showing my coupon setup and the ID selection.

Is the attachserail plugin configured correctly? Will this only be added to a confirmation order email when that specific product is purchased?

I'm happy to supply you with a login to check!

Thanks again

Lee

Jerome,
Apologies I've not worked at this for a few weeks and just picking it back up.

Would it be possible for me to send you a login to review what I have done? I have tried a number of test purchases with changed settings but not getting any code generated or sent via email!

Thanks
Lee