Audio post? Is this post type created by a plugin?
No, the area inside WordPress that allows you to put an audio link when you chose the audio post type.
There is no such area in the default WordPress. Maybe a plugin or your theme added it, and that doesn’t work with the new editor.
Look for an update for your theme or plugins. Or install the Classic Editor plugin to get the old editor back.
There is an area, and has been an area on every WordPress site I have ever had.
It is where you choose Post Type: Audio, and where you put that audio link in so that audio is not just embedded into the page.
That is created by the theme you are using. WordPress does not provide that “type” by default. Please provide a link to your site and/or a screenshot of this.
