How to implement load more ?

[mytc]

I am change to this from flatlist, but I can't make the load more features works.

<UltimateListView

          onFetch={this.onFetch}
           keyExtractor={(item, index) => item.key}
           item={this.renderItem}
         refreshing = {this.state.refreshing}
         onRefresh={() => this.refreshData()}
         ListFooterComponent={this.Loadmore}
         onEndReached={this.handleLoadMore}
         onEndReachedThreshold={50}
         initialNumToRender={10}
         ItemSeparatorComponent={this.renderSeparator}
         getItemLayout={(data, index) => (
           {length: ITEM_HEIGHT, offset: ITEM_HEIGHT * index, index}
         )}
         paginationFetchingView={this.Loadmore}
     
         arrowImageStyle={{ width: 20, height: 20, resizeMode: 'contain' }}
         autoPagination={true}
         onEndReachedThreshold={10}
         paginationBtnText="Load More"
         updateDataSource={this.state.data}
       />
..........
onFetch = async(page = 1, startFetch, abortFetch) => {
     page = this.state.page
       try {
           //This is required to determinate whether the first loading list is all loaded.
           let pageLimit = 50;
          // if (this.state.layout === 'grid') pageLimit = 60;
           let skip = (page - 1) * pageLimit;

           //Generate dummy data
           let rowData = this.state.data

           //Simulate the end of the list if there is no more data returned from the server
           if (page === 100) {
               rowData = [];
           }

           //Simulate the network loading in ES7 syntax (async/await)
           await this.sleep(2000);
           startFetch(rowData, pageLimit);
       } catch (err) {
           abortFetch(); //manually stop the refresh or pagination if it encounters network error
           console.log(err);
       }     
   };

Previously in flatlist I am using onEndReached to trigger the load more feature, where in the method, I change the page state and calling fetch data from web server and finally update the data source (state.data).

But how it doesn't work in this. I am fairly new in RN and es6, must be something i missing. Can anyone show me how?