Whenever i load my project it show me undefined index error?

Whenever I load my project it throws an error

undefined $accessToken

My Script

 <script>      Twilio.Video.createLocalTracks({         audio: true,         video: { width: 300 }      }).then(function(localTracks) {         return Twilio.Video.connect('', {             name: '',             tracks: localTracks,             video: { width: 300 }         });      }).then(function(room) {         console.log('Successfully joined a Room: ', room.name);           room.participants.forEach(participantConnected);           var previewContainer = document.getElementById(room.localParticipant.sid);         if (!previewContainer || !previewContainer.querySelector('video')) {             participantConnected(room.localParticipant);         }           room.on('participantConnected', function(participant) {             console.log("Joining: '"   participant.identity   "'");             participantConnected(participant);         });           room.on('participantDisconnected', function(participant) {             console.log("Disconnected: '"   participant.identity   "'");             participantDisconnected(participant);         });      });      // additional functions will be added after this point  </script>  

https://stackoverflow.com/questions/65559544/whenever-i-load-my-project-it-show-me-undefined-index-error January 04, 2021 at 04:17PM