import * as FileSystem from 'expo-file-system';
    import * as MediaLibrary from 'expo-media-library';

   const handleDownloadImage = async () => {
        await MediaLibrary.requestPermissionsAsync();
        const localuri = await FileSystem.downloadAsync(
            'https://64.media.tumblr.com/a92e72902106507c59ff8d0ca26abfc0/1d7f633f39b0a908-34/s1280x1920/a7073bbdeb1033b989e040fd216266be8ba31341.jpg',
            FileSystem.documentDirectory + 'demo.jpg'
        );
        const asset = await MediaLibrary.createAssetAsync(localuri.toString());
        const album = await MediaLibrary.createAlbumAsync('DownLoads', asset);
        console.log(album);
    };

I was unable to save an image to the download folder, I used expo without 2 folders android and ios