Planet Fitness implements QR codes as one way for their members to access their gym locations. Generally, you will find QR codes at the front desk or entrance of the gym or sometimes on marketing flyers. Some gyms also have dedicated scanners that you can use to check-in. To use the QR code, you need to have the Planet Fitness app downloaded on your phone, log in, and select the "Scan Now" button in the app to scan the QR code. Once you scan the code, you'll be checked in, and the gym will have a record of your entry. If you're having difficulty locating the QR code, you can ask the gym staff for assistance.