As of the current version of Mendix (8.1.1), this would require a JavaScript action to accomplish in a native app. We’ll see a method to handle this out of the box in the near future.
building a react widget and call api via
import React, { Component } from 'react'
class App extends Component { ... componentDidMount() { fetch('http://jsonplaceholder.typicode.com/users')
.then(res => res.json())
.then((data) => { this.setState({ contacts: data }) })
.catch(console.log) }
// More code here.
}