To redeem a Webflow promo code, follow these steps:

1. Go to the Webflow website.
2. Navigate to the pricing page.
3. Choose a plan (e.g., Basic).
4. Click on "Add promo code".
5. Enter the promo code and select "Apply".
6. Complete the payment.

For Webflow Ecommerce, there are additional steps to add a discount code:

1. Click into the Ecommerce panel on the left toolbar.
2. Select Discounts and New discount.
3. Under Basic info, choose Generate code to automatically generate a random discount code or manually enter a custom discount code.
4. Under Discount details, choose from 3 discounts: Percentage, Fixed amount, Free shipping.
5. Set valid dates for the discount codes.
6. Add discount restrictions under the Restrictions section.
7. Publish and test your site.

Remember, the discount code is already pre-filled so you can see the discounted price on the right side. Enter your personal information and credit card details as requested on the screen. Note that Webflow only accepts credit card payments.

Hope this helps! If you need more information, feel free to ask.