Podcast.menu:

To use, simply upload mp3s that you want to use as podcasts.  The url
scheme should look like: https://podcast.menu/[username]/[podcastName]/([episode]).

If you want to create a podcast for user 'john' called 'Turmeric', you
could create it by uploading an mp3 to it with curl:

    curl -X POST 'https://podcast.menu/john/Turmeric/1.mp3' --form 'upload=@./1.mp3' 

You could then add more mp3s to the podcast by uploading new files:

    curl -X POST 'https://podcast.menu/john/Turmeric/2.mp3' --form 'upload=@./2.mp3' 

Then in your podcast player, simply add the following podcast URL:

    https://podcast.menu/john/Turmeric

If you wanted to create a new podcast, simply repeat the process replacing
Turmeric with your new podcast name:

    curl -X POST 'https://podcast.menu/john/Curry/2.mp3' --form 'upload=@./1.mp3' 

To get a progress meter install pv (pipeviewer, available on brew or
your favorite package manager) and use that to pipe your mp3 into curl:

    < 3.mp3 pv | curl -X POST 'https://podcast.menu/john/Curry/3.mp3' --form 'upload=@-' 

You could of course also use something like Postman to upload.