Background Fetch

I’m using the Ionic Background Fetch plugin as it says at but the issue that I have is that I don’t have a way to configure the callback function that should be executed on user’s prime time as the doc says.

const config: BackgroundFetchConfig = {
stopOnTerminate: false, // Set true to cease background-fetch from 
operating after user "closes" the app. Defaults to true.

 .then(() => {
 console.log('Background Fetch initialized');


 .catch(e => console.log('Error initializing background fetch', e));

where is supposed to be provided the callback function? the configure function only takes one argument “config” Does anyone could make it to work? Thanks in advance!