How to scan devices with Bluetooth plugin in Cordova/Ionic? (iOS)

I have an Ionic 3 application. I am looking for a plugin or solution to connect my iPhone to a bluetooth tag reader just to read tag numbers from Tag Reader. I am using iPhone 5S (iOS 12) and tag reader is AllFlex RS420. The tag reader is paired and connected to the phone. The tag reader is being scanned in some other applications like Allflex app or MagicSerialKeys.

I just need a simple bluetooth plugin example for ios devices that can work with my tag reader just to read data (no writing).

I have tried the bluetooth serial plugin. https://ionicframework.com/docs/native/bluetooth-serial

It works fine with android devices but it’s not working with iOS devices. I have downloaded the code from this website. https://medium.com/@maneeshaindrachapa/bluetooth-serial-interface-with-ionic-66c823792166

The initial problem is, the tag reader is not being scanned in the list() method of the plugin for iOS devices and there are no errors in console.

I looked into other plugins as well but they are complicated as they have advertising data and services. I am not sure how services work or how to find a particular service just to read data. For example, the one below: https://ionicframework.com/docs/native/ble

All of the code is in this repository: https://github.com/maneeshaindrachapa/sHome

Please let me know if any other information is required. I am new to Stack overflow. Thank you so much.