failed HandshakeException: Connection terminated during handshake error in http package when I using firebase function

Question

I'm using http package to get the firebase cloud function data, I'm getting error in the console as

failed HandshakeException: Connection terminated during handshake

I added internet permission in the manifest file, what went wrong here

static Future<List<List<MajorCentralBankRules>>> getMajorCentralRules() async 
  {

      try{
          final response=await http.get(majorcentralbankurl);
          if(response.statusCode==200)
          {
          final List<List<MajorCentralBankRules>> majorCentralBankRules = majorCentralBankRulesFromJson(response.body);

              print("successful");

              return majorCentralBankRules;
          }
          else
          {
            majorCentralErrorCode=response.statusCode.toString();
            print(response.statusCode);
            print('failed');
          }
      }catch(e)
      {
        print('failed $e');
        majorCentralErrorCode=e.toString();

      }
  }