How to know BG96 (RAK8212) worked or not?

do you have whole one program( include AT ,HTTP , SMS ) for testing? we can't get any http data by executing your examples, there is no any error message .

below are some AT command responses .

+CEREG: 2,1,"2EB","B2A3106",8
AT+QNWINFO
+QNWINFO: "CAT-M1","52501","LTE BAND 3",1300
AT+QSPN
+QSPN: "Singtel","Singtel","Singtel",0,"52501"
AT+QCSQ
+QCSQ: "CAT-M1",-125,0,8,0

AT+QCSQ
+QCSQ: "CAT-M1",-67,-93,130,-9
connectionReady

there is one error message "ERROR { "code": -15,
"message": "no response"
}
after we changed the code as below

function connectionReady() {
    
   console.log("connectionReady.");
    
  var http = require("http");
  http.get("http://www.pur3.co.uk/hello.txt", function(res) {
    res.on('data', function(data) {
      console.log(data);
    });
  })
  .on('error', function(err) {
      console.log('ERROR', err);
   });
}

I'm pretty sure the code in https://www.espruino.com/RAK8212 is tested and works.

However what you're trying to do here - using the built in HTTP module for NB-IoT - won't work, as it isn't supported by Espruino at the moment. You will have to do all NB-IoT communication via AT commands for the time being.

If the link that's provided (https://wolfgangklenk.wordpress.com/2018/10/12/espruino-on-rak8212-accessing-the-nb-iot-nb1-modem/) doesn't give you enough info, you should ask RAK for some examples of what AT commands need to be sent for NB-IoT communications.

My SIM card is CAT-M1

Ok, I've just looked into this and there were a few issues with the QuectelBG96 module by the look of it.

If you download the 'cutting edge' firmware from http://www.espruino.com/Download#RAK8212 it should now hopefully be fixed.

While you may still have issues with CAT-M1, normal TCP/IP comms should now work fine