How to call an API on left scroll and call another API on right scroll using Flat List (horizontal) in React Native?

Question

I have implemented Flat List (Horizontal) in React Native. I have used onEndReached and onEndReachedThreshold to call an API. So when I scroll right a API gets called, but am not able to scroll left and call a different API on that, as my initial page number is '0' so won't be able to do left scroll.

So basically I need to set a page number for example as '3' so that i can scroll to left as well as right. And then my concern is how would I know that left scroll has been triggered or right to call different API's on both.

The things which I have implemented right now for right scroll is as below :

render() {
return (
    <FlatList
      horizontal
      pagingEnabled
      data={this.state.data}
      renderItem={({ item }) => (
      <View>
      <Text> Details </Text>
      <ScrollView>
        <ListItem 
          title={item.name.first}
          subtitle={item.email}
        />
        <ListItem 
          title={item.name.last}
          subtitle={item.email}
        />
        <ListItem 
          title={item.address}
          subtitle={item.email}
        />
      </ScrollView>
      </View>
      )}
      keyExtractor={item => item.email}
      onRefresh={this.handleRefresh}
      refreshing={this.state.refreshing}
      onEndReached={this.handleRightLoadMore}
      onEndReachedThreshold={10}
    />
);

}