Hi,
Please note I am not an official support person but a customer like you.
As per my experience, the app released by WPLMS is perfectly fine however the errors are due to setting up ionic environment which is actually a nightmare.
Please make sure the following are installed with the exact versions and your app might work. This is the exact version that I use for my app.
1. Node.js 12.16.3
2. Ionic – 5.14.6
3. Cordova 9
4. Ionic angular 3.9.2
5. Ionic App scripts: 3.2.4