Coupon redemption form I just updated the Drupal Commerce installation to beta 7 which includes support for promotions and coupons. I just can't seem to get the coupon redemption form in the cart to test this functionality. I checked the cart view, there is a field 'Coupon' in the global footer, but that is just meant to show the already activated coupons I believe. At least it didn't do anything for me. 

I tried to add 'Coupon' to my relationships in the view, but this broke down the website (incorrect query generated).

In the code I also noticed the CouponRedemption FormElement. I'm not sure how to add this to my cart (view), but that seems to be what I need.
I finally figured out the answer: the functionality has simply not been coded. Applying the patch from this issue: https://www.drupal.org/node/2792653 (patch #95 is the latest right now) will add a checkout pane for entering coupon codes. It is still not available on the cart page as you would expect in a webshop, but at least visitors can enter a coupon code.

You can place the checkout pane using Commerce->Configuration->Checkout flows->pick your flow by clicking 'edit'->Coupon redemption pane.