PODCAST (with .m4a file) created by Notebook LM
M4A file -->
PODCAST (with .mp3 file) converted from .m4a file via https://cloudconvert.com/m4a-to-mp3
MP3 file -->
Upload your audio file (M4A, MP3, WAV, etc.) to Google Drive.
Right-click the file, select "Share," and change permissions to "Anyone with the link" (Viewer).
Copy the shareable link.
In Google Sites, double-click an empty space, choose/insert Embed, then paste the URL.
Tip: For a better preview link, change /view?usp=sharing at the end of the Drive URL to /preview