To use Open Formula promo codes, follow these steps: 1. Choose a promo code that fits the order. 2. Navigate to the Open Formula website and add desired items to the shopping cart. 3. Proceed to the checkout page where there will be a field to enter the promo code. 4. Paste the promo code in the designated box and click apply. 5. Review the savings before finalizing the checkout process.
Remember, each promo code has its own terms and conditions, so ensure to check these before applying the code. Enjoy shopping!