You just need to add the code below to the blog post in HTML mode or paste in the HTML/Javascript gadget. Replace url-of-audio-file with your audio file's url. You can host your audio file on Google Drive or anywhere else. <audio controls autoplay > <source src="url-of-audio-file" /> If you cannot see the audio controls, your browser does not support the audio element </audio>
Blogger's questions & answers in tl;dr style.