As mentioned above it truly is recommended you have your bird examined by an avian vet. Out of curiosity I googled this question " Is there a mail in test for Psittacine Beak and Feather Disease ". I found this information:
Testing for Psittacine Beak and Feather Disease (PBFD) is primarily done using a PCR (Polymerase Chain Reaction) test, which detects the DNA of the circovirus. Samples required for the test usually include a small whole blood sample, a dried blood spot on a specialized card, or a fresh blood feather. The link below has information on disease testing and other testing as well.
You can order a test kit online, however, it is not a substitute for on hand examination by a vet. It may though give you an answer if it could be PBFD. I don't know much about the disease so I would suggest reading up about it. It could be simply plucking. Some birds can turn into stress pluckers. What is the history with your bird? How long have you had this bird and is it the only one you have? Kept indoors? Outdoor aviary? Share as much as you can.
iqbirdtesting.com