Automatic Audio plugin not uploading

I’ve downloaded and activated this plugin offered by AutomaticJack

https://www.automaticjack.tv/descargas/automatic_wp_player.zip

But I cannot get it to upload a small wav file.

I get an error message:

The requested method POST is not allowed for the URL /muse/wp-music/cgi/upload.pl.

I’ve set permission to 777.

I don’t know what else to do.

There are no other plugins for wav files that I know of.

Any advice is appreciated.

David
https://glitteringstew.com/muse