App Availability Code Error

I am trying to use App Availability extension. But i am getting error even when i am using the same example. Please Take a look below.

    let app;
    if ('ios')) {
      app = 'twitter://';
    } else if ('android')) {
      app = '';
      (yes: string) => console.log(app + ' is available'),
      (no: string) => console.log(app + ' is NOT available')

Where does this variable come from?
Are you using Ionic Native?

yes i am using Ionic Native

What error are you getting? Or should we guess?

Argument of type '(yes: string) => void' is not assignable to parameter of type '(value: boolean) => void | PromiseLike<void>'.
  Types of parameters 'yes' and 'value' are incompatible.
    Type 'boolean' is not assignable to type 'string'.

This is the error…

Their example (Ionic native) seem to be wrong. The check function returns a Promise<boolean> as per the documentation and the error message say, not a Promise<string> like in the example.
Try this

    () => console.log(app + ' is available'),
    () => console.log(app + ' is NOT available')

If that doesn’t work then maybe this

    (available: boolean) => {
        if (available) {
            console.log(app + ' is available')
        } else {
            console.log(app + ' is NOT available')

Either way I think the documentation is wrong if you’re getting an error with the example