Dynamic time-limited codes cannot be generated

Hi @Thomas0807, 

Thanks for being a part of our community! I am seeing a support ticket on this as well:

If you are looking to incorporate this link {{ event.extra.checkout_url }}&discount={% coupon_code 'Exit' %} directly in your Discount at checkout sign up form, unfortunately it will cause an issue because it is not possible to create a button in a sign-up form that a customer can click to automatically apply it to the shopping cart. I'm sorry for the inconvenience this causes. The syntax {{ event.extra.checkout_url }} only works within flow emails triggered by the Started Checkout metric. 
 
This is also called out in our help center article How to add link that applies a coupon code to a Shopify cart. This functionality only works in emails, not sign-up forms. 
 

 
If you want the coupon code to appear in the success page of your sign-up form, here is more information on that: How to add coupon codes to sign-up forms

~Chloe