Check whether you have an affected model with the following steps:
Choose About This Mac from the Apple menu in the upper-left corner of your screen. Confirm your model is "MacBook Pro (Retina, 15-inch, Mid 2015)."
If you have this model, please then enter the serial number in the "Eligibility" section of the below webpage:
A more comprehensive guide to finding your Apple product's serial number is available here:
Once you have checked if your model is affected follow the instructions on the webpage to arrange a free repair.