App.tsx

import React, { useEffect, useState } from 'react';
import { Platform, Text, View } from 'react-native';

import Purchases, { PurchasesOffering } from 'react-native-purchases';

const APIKeys = {
  apple: "your_revenuecat_apple_api_key",
  google: "your_revenuecat_google_api_key",
};

export default function App() {
  const [currentOffering, setCurrentOffering] = useState<PurchasesOffering | null>(null);

  useEffect(() => {
    const setup = async () => {
      if (Platform.OS == "android") {
        await Purchases.configure({ apiKey: APIKeys.google });
      } else {
        await Purchases.configure({ apiKey: APIKeys.apple });
      }
      
      const offerings = await Purchases.getOfferings();
      setCurrentOffering(offerings.current);
    };

    Purchases.setDebugLogsEnabled(true);

    setup()
      .catch(console.log);
  }, []);

  if (!currentOffering) {
    return "Loading...";
  } else {
    return (
      <View>
        <Text>Current Offering: {currentOffering.identifier}</Text>
        <Text>Package Count: {currentOffering.availablePackages.length}</Text>
        {
          currentOffering.availablePackages.map((pkg) => {
            return <Text>{ pkg.product.identifier }</Text>
          })
        }
      </View>
    );
  }
}

L26: Purchases.setLogLevel(LOG_LEVEL.DEBUG);

I needed this: Purchases.setLogLevel(Purchases.LOG_LEVEL.DEBUG);

Purchases.configure is handled as a promise here, but the typescript typings shows it as having a void return type