How to make a function that fetches more content from an API for the pull to refresh in ionic

how can i implement it in my project
This is my home.html

<ion-refresher (ionRefresh)="doRefresh($event)">
    <ion-refresher-content pullingIcon="arrow-dropdown" pullingText="Pull to refresh" refreshingSpinner="crescent" refreshingText="Refreshing...">

This is the home.ts

ionViewDidLoad() { = 'none';
    setTimeout(() => {
      this.splash = false; = 'flex';
    }, 4000);

Implement the doRefresh method as is probably also described in the documentation.