To use a Baby Doppler promo code, follow these steps: 1. Choose the items to purchase and add them to the shopping cart on babydoppler.com. 2. Proceed to the checkout process. 3. During checkout, find a field to enter the promo code. 4. Copy the desired Baby Doppler coupon code from the source. 5. Paste the code into the field and click apply to receive the discount. Remember, the code must be entered exactly as it appears. Enjoy shopping!