Problems to display audio in a post

I need help.

When I insert the audio into a post, does not look good, because the player can not see the buttons play and sound.

You can see it here:

https://www.anahernandezserena.com/entrenando-emprendedores-lanzarse-al-vacio-pero-con-red-receta-5/

I’m desperate and do not know what to do.

Thank you,