Ionic 4+ MQTT

Hello, I’m want to create an ionic app that uses MQTT.
I tried using this rep :
https://github.com/walterchau/ionic-mqtt

Importing this into modules results in multiple errors.

How to recreate the issue:
-create a blank ionic 4 project.
-follow implementation steps in rep.

my ionic info

Ionic:

ionic (Ionic CLI) : 4.12.0 (/usr/local/lib/node_modules/ionic)
Ionic Framework : @ionic/angular 5.2.3
@angular-devkit/build-angular : 0.901.11
@angular-devkit/schematics : 9.1.11
@angular/cli : 9.1.11
@ionic/angular-toolkit : 2.2.0

System:

NodeJS : v12.13.0 (/usr/local/bin/node)
npm : 6.12.0
OS : Linux 5.3

Any feedback can be helpful. Thanks :innocent: