# Optional settings

The following table explain the additional settings for your Android app:

<table><thead><tr><th width="262" valign="top">Call this method…</th><th valign="top">To…</th></tr></thead><tbody><tr><td valign="top"><code>handleConfigurationErrors</code></td><td valign="top">Receive alerts for configuration-related issues.</td></tr><tr><td valign="top"><code>handleCardProcessingResponse</code></td><td valign="top">Monitor issues during the card payment processing.</td></tr><tr><td valign="top"><code>lcdDisplay</code></td><td valign="top">Monitor the rest of the communication during the card payment processing.</td></tr><tr><td valign="top"><code>successfulTransactionToken</code></td><td valign="top">Receive a JSON Web Token (JWT) after a successful card read to process the payment.</td></tr></tbody></table>