const accessToken = new AccessToken(
TWILIO_ACCOUNT_SID,
TWILIO_API_KEY,
TWILIO_API_SECRET,
);
    you have to pass the key identity inside this block


const accessToken = new AccessToken(
TWILIO_ACCOUNT_SID,
TWILIO_API_KEY,
TWILIO_API_SECRET,
{ identity : yourIdentityValue }
);