Coupon Code in Conformation Email

Hi I am having trouble with my emails, I can’t get the ‘coupon code’ to come through on my admin notification email. Eg use ‘XMAS’ discount code on checkout that works fine (its wrapped in the form just as this

[s2Member-Pro-Stripe-Form level=“3” ccaps="" desc=“10WK Challenge: $52.50 upfront” cc=“AUD” custom=“www.lukeheathfitness.com.au” ta=“0” tp=“0” tt=“D” ra=“52.50” rp=“3” rt=“M” rr=“0” coupon="" accept_coupons=“1” default_country_code=“US” captcha=“0” /]

When I use this code on admin emails it comes through blank:
I use %%full_coupon_code%% or %%coupon_code%% in my admin email it does not pull through.
I have read this https://s2member.com/kb-article/full_coupon_code-in-admin-notification-email/ but I am still confused of how to display which discount coupon code is being use on checkout for my admin emails
I am an s2 pro member
Can you please let know where I am going wrong?