Using a web browser:

When remote voice tracking via a web browser, click the Settings button (cog icon) in the Segue Editor to open the audio settings. From here, you can select your preferred Microphone Device for recording and Playback Device for monitoring audio. These changes take effect immediately without needing to restart your session.

Using PlayIt VoiceTrack:

In PlayIt VoiceTrack, you can change your audio devices by going to File > Settings from the main menu. Under the audio device section, select your Microphone Recording device for voice track recording and your Segue Editor Playback device for monitoring audio during recording. You can also access these settings quickly by clicking the Settings button while in the Segue Editor. Click OK to save your changes.

For both methods, make sure you've selected a microphone device that doesn't record playback audio to avoid an echo effect in your recordings. You should wear headphones connected to your playback device to prevent your microphone from picking up the music.