sample.js

const saveSnapshotToServer = async (snapshot) => {
    // async code here.
    // Send a snapshot to the server, store it locally somewhere, etc.
}

const overrideCallback = (Provider) => {
    // Extend default behavior
    class MyOverride extends Provider {
        async getSnapshot() {
            // Call super to access vanilla platform behavior
            const snapshot = await super.getSnapshot();
            // Perform any additional logic needed
            const modifiedSnapshot = { ...snapshot, answer: 42 }
            await saveSnapshotToServer(modifiedSnapshot);
            return modifiedSnapshot;
        }
    }
    // Return instance with methods to be consumed by Platform
    return new MyOverride();
};
fin.Platform.init({ overrideCallback });