The code does not work though it is stated it is valid for first 4 orders ?

Hey, I recently started ordering Walmart and on its' official website, there is a promotion code for 4 grocery orders. After using it 2 times succesfully, when trying now, it says "Sorry! This promo code applies only to first-time online grocery orders".

Is there a way to fix it * or what should I do ?

Thank you.