The NFC Reader is in an Always-On Mode in the iOS Apple Operating System. iOS Users do need to take any action to turn NFC on.
To enable NFC on your device, you access it through generally through;
Settings>Connections>NFC and Contactless Payments
NOTE: Some Android devices may have a slightly different Settings Menus. See you device manufacturers' instructions for how to activate NFC.
NFC Reader Location
It is important you understand where the reader is located, so you know which part of the phone you need to TAP & HOLD to the freshOps Tag.
NFC TAP & HOLD Check-In Explained.