Make sure you have the Amazon Alexa app installed on your device. If necessary, download the Alexa app from Google Play or the App Store. With your headphones connected to your device, follow the instructions in the app to set up Alexa.
Note: Amazon Alexa isn’t available in all languages and countries.
If pressing the Voice Assistant button is not activating Alexa correctly, here are a few things you can try:
Make sure the Voice Assistant button is set to Amazon Alexa. In the Bose Music app, select Settings > Voice Assistant > Alexa. You may also have to tap “Go to App” to finish setting up your headphones with Alexa
Reboot your device
Connect your mobile device to Wi-Fi®
Disconnect Bluetooth® and reconnect
Clear the Bluetooth device list from your headphones by holding the Power/Bluetooth button for ten seconds. You should hear "Device list cleared" from the headphones. In your device, go into Bluetooth settings and remove the headphones. Reconnect the headphones to your device.