Can I submit an extra letter of recommendation? No, unless it is a peer or alumni recommendation. There are separate forms for these recommendations and, if submitted on your behalf prior to the time when you submit your application, you are eligible for an application fee waiver. Please allow at least two to three days for processing.
You will be eligible for an application waiver with an alumni referral, which means you need to find an alum to fill your basic information like name and email on the online referral form. You don't need to have a recommendation letter from Fuqua alumni, if you only want to have the fee waived. But I think the recommendation would enhance your chances of being admitted.