Yes, you can use pre-recorded audio in multiple formats, including WAV and MP3.
Pre-recorded messages can be used on a IVR scenario, when you want to play messages in a menu scenario instead of using TTS, and it can also be used on a callout scenario, when the customer want to trigger a call to a destination number, and play a message directly, such as a PIN code for a OTP (One Time Password) call.
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