observeHistory only working once & observeSteps is not working about react-native-google-fit HOT 4 CLOSED

   I am using react native 4.9 and samsung s7 api 24
  here is the code.

   import React, { Component } from 'react'
   import Styles from './styles'
   import GoogleFit from 'react-native-google-fit'
   import Reactotron from 'reactotron-react-native'
   import  jsonFormat from 'json-format'

  import {
View,
Text,
 } from 'react-native'
 
 class Walking extends Component {


timer:number = 0;

constructor(props)
{
	super(props);

        GoogleFit.authorize((err, result) => {
        if(err) {

	alert('olla')
        }
        else {
         
            GoogleFit.observeHistory((steps)=>{
                Reactotron.log(steps)
            });

            const options = {
                startDate: "2017-01-01T00:00:17.971Z",  // required ISO8601Timestamp
                endDate: (new Date()).toISOString()     // required ISO8601Timestamp
            };

            GoogleFit.getDailyStepCountSamples(options, (err, res) => {
                if (err) {
                    throw err;
                }
                Reactotron.log(steps)

            })
		}

    });

    this.state ={
    	steps:0
	}

}

render() {

	return (
		<View style={Styles.container}>
			<Text>{this.state.steps+""}</Text>
		</View>
	)
}