Do Asus Rewards Work with eBay Purchases? [SOLVED]

Hi all,
So I've recently purchased the FX505DU-AL042T at a 20% discount coupon on eBay through Computer Alliance seller.

(Link:https://www.ebay.com.au/itm/ASUS-FX505DU-AL042T-15-6-AMD-Ryzen-7-Notebook-Win-10-Home/173900595628?_trkparms=aid%3D111001%26algo%3DREC.SEED%26ao%3D1%26asc%3D20160908105057%26meid%3D7351ab8c8db34d6a827d105a627885ec%26pid%3D100675%26rk%3D2%26rkt%3D15%26sd%3D254218698053%26itm%3D173900595628&_trksid=p2481888.c100675.m4236&_trkparms=pageci%3A8ebdae4e-8b79-11e9-9f33-74dbd180c0e3%7Cparentrq%3A4151632416b0a9cb6bf029dfffed9ec1%7Ciid%3A1)

In the description it states the Asus rewards claimable stuff, including the $100 cash-back and the TUF headset. However on both of these websites (asusrewards.com and asusrewards.com/cashback) in the terms and conditions it states that eBay purchases aren't valid. Is it at all possible to redeem these offers? Does Computer Alliance send you their own receipt?

Thanks,
Alpha

EDIT:
Computer Alliance has confirmed (via eBay message and their official website contact) that they send their invoice with the order. I assume most sellers advertising the deals will do the same, but I guess you should check with them first.