The code found in Samsung Pay (check the images in the slideshow at the bottom of this article) directs the mobile payment app to look for an in-display fingerprint scanner so that it can adjust the UI to make more room for the user to touch the screen and verify a purchase. The code also specifically refers to the "Beyond in-display FP scanner." Beyond is Samsung's internal code name for the Galaxy S10 series.
Unlike handsets like the OnePlus 6T that already offer an in-display fingerprint scanner, Samsung will reportedly turn to Qualcomm's cutting edge ultrasonic reader. According to Qualcomm, this method is more accurate and faster than the optical readers used on current models. The optical readers compare pictures of a fingerprint taken during setup, to the one being presented now. With Qualcomm's system, ultrasonic waves bounce off the fingertip allowing the phone to create a more precise 3D model that must be matched in order to verify an ID.