You can purchase custom-fit goggles through the official Magic5 website. The company offers a few different models, regular goggles with clear lenses and tinted for outdoor swimming. If you need both, Magic5 offers a bundle deal with both models. Lens color options are slightly limited, but I am now picky about it.
Once you go through a check-out, you'll need to download the Magic5 app and scan your face. The whole scanning process is similar to your phone's FaceID, where your camera takes a face scan from different angles.
Once that step is done, you'll have to wait for approximately 2 weeks to receive your new pair of Magic5 swim goggles. If your swim goggles don't fit your face, Magic5 will attempt to create the best goggles again with a new face scan.