Revenuecat React-Native offerings gets empty object?

I'm using revenuecat for in-app purchase I want to add "Monthly subscription", So I follow the Docs for configuration.and set up everything as they wrote.

For code part

In App.js

import Purchases from 'react-native-purchases';export default class App extends React.Component {  componentDidMount() {...    Purchases.setDebugLogsEnabled(true);    Purchases.setup('apiKey');  }......}

here a specific screen here should I return the price, name, time "monthly" and other data (display product)

import React, {Component} from 'react';import {View, Text} from 'react-native';import Purchases from 'react-native-purchases';export default class OneMonthPurchases extends Component {  getOfferings = async () => {    try {      const offerings = await Purchases.getOfferings();      console.log('offerings', offerings); // offerings: {"all": {}}    } catch (error) {      console.log('error when get offerings', error);    }  };  componentDidMount() {    this.getOfferings();  }  render() {    return (<View><Text>One Month Purchases</Text></View>    );  }}

but when I log offers I got offerings: {"all": {}}So how can I solve it Or I miss something?

Note: I test on simulator