How to Use Samsung Pay
To use Samsung Pay on your Galaxy S7, first pick something to buy at a store. Have a clerk ring it up and tell him you will pay with a credit card. Swipe the screen upward. You see the screen shown here.
Run your finger over the Home button, and you see a screen similar to this one.
As seen, you should either hold your phone against where the credit card reader would read the magnetic stripe or where there is the contactless payment system logo if it is available.
The semicircle above your signature will start counting down, and your phone will vibrate to let you know that it is transmitting. You will hear a beep if it all goes through. If it fails for some reason, you can try again simply by rescanning your fingerprint.
This process works with the vast majority of credit card readers. This does not work well, however, with credit card readers where you insert your card into the machine and pull it out quickly. This type of reader is mostly used on gasoline pumps. Sorry.