Background runner plugin: backgroundrunner.dispatchEvent error

## Bug Report

### Plugin(s)
"@capacitor/background-runner": "^1.0.5",

### Capacitor Version

@capacitor/cli: 5.0.5
@capacitor/core: 5.0.5
@capacitor/android: 5.0.5
@capacitor/ios: 5.0.5

### Platform(s)
Android, ios

### Current Behavior
I'm using capacitor in a ionic+ stencil application

I'm not able to start correctly BackgroundRunner plugin

This is my runner.js location

this is my capacitor.config.ts

```
{
"appId": "com.myapp.app",
"appName": "MyApp",
"webDir": "www",
"server": {
"androidScheme": "https"
},
"ios": {
"handleApplicationNotifications": false
},
"plugins":{
"BackgroundRunner": {
"label": "com.myapp.app.check",
"src": "runner.js",
"event": "checkIn",
"repeat": true,
"interval": 2,
"autoStart": false
}
}
}
```

And I have this error


Is a problem cause by a wrong path for the runner.js file or something else?
I'm not able to make it work!

### Expected Behavior

Plugin runs correctly