Coupon Redemption on iPad

For the life of me I can’t find the place to redeem a coupon on iPad. I’ve used it in the past, fairly certain it was on the shop page.
Any help?
Is it possible to redeem via this website?

It should be on the shop page in the top righthand corner above the battlechest.

oh, you can play on an ipad?
I thought it was just recently being released on android.

…I’m going on a business trip next week…

Thanks for replying. Sadly it’s no longer there. I’ve linked a screenshot