Beginer: How to send data from puck to webpage or text file

Ok, all I can think is that maybe we're causing problems by changing the NFC URL while the NFC connection is active. Maybe try:

var nfcOn = false;
NRF.on('NFCon', () => { nfcOn = true; });
NRF.on('NFCoff', () => { nfcOn = false; });
setInterval(() => {
  if (nfcOn) return; // don't change if NFC on
  var currentTime = new Date();
  NRF.nfcURL('http://192.168.1.154/studentsystem/details.php?time=' + currentTime.toISOString().substr(0, 16));
}, 60000); // once a minute