Turn on your JBL Xtreme and pair it with your phone via Bluetooth (Settings → Bluetooth → JBL Xtreme).
Launch JBL Connect. It should detect your Xtreme automatically. Tap on the speaker icon. jbl xtreme update firmware
Look for a gear icon (Settings) or a section labeled “Speaker Version” / “Firmware Update”. Tap “Check for updates”. Turn on your JBL Xtreme and pair it