React Native Share doesn't share files

Question

I am trying to share a JSON file of a Realm database using React Native. I have written the following code:

import { Share } from "react-native";
    const shareData = async () => {
        try {
            const realm = await Realm.open({ "schema": [schema1, schema2] });

            const schema1Records = realm.objects("Schema1");
            const schema2Records = realm.objects("Schema2");

            const schema1Json = JSON.stringify(schema1Records, null, 2);
            const schema2Json = JSON.stringify(schema2Records, null, 2);

            const fileContents = `{\n  "schema1": ${schema1Json},\n  "schema2": ${schema2Json},\n}`;
        
            const fileName = "database.json";
            const fileUri = `${FileSystem.documentDirectory}${fileName}`;

            await FileSystem.writeAsStringAsync(fileUri, fileContents, { "encoding": FileSystem.EncodingType.UTF8 });

            const result = await Share.share({
                "message": fileContents,
                "title": "Database",
            });

            realm.close();
        } catch (error) {
            console.error("Error sharing database:", error);
        }
    };

This shares the correct database as plain text, in JSON format. However, the text is shared instead of the JSON file. Why is this? How can I fix it?

I have also attempted to use the react-native-share package. However, I receive: TypeError: Cannot read properties of undefined (reading 'ios'). I have configured the app.json file for this package. However, due to the fact I am building an Expo app and have not yet run npx expo prebuild, I have not been able to modify the android and ios directories.