To apply a discount code on an order at Gearx.com, customers should first ensure they have selected the items they wish to purchase and added them to their shopping cart. Once ready to proceed to checkout, there should be a designated field labeled for discount codes or promotional codes within the checkout page. Customers can enter their code in this field and then click on the appropriate button, typically labeled as "Apply" or similar, to ensure the discount is applied to their order total. It is important to check whether the discount code has any specific terms and conditions, such as expiration dates or minimum purchase amounts. If the discount does not appear to be working, verifying that the code has been entered correctly is advisable. For any additional assistance or troubleshooting, it may be beneficial to check the current Gearx.com website for more specific information regarding the discount application process.