How do I get the URL being sent to a media player for tts?

I have Hass.io set up on a raspberry pi.
I set up a couple of orange-pi’s with MPD media player to use as cheap TTS notification announcers.
The media players show up fine on lovelace, and I can have them play a small mp3 file that I placed in the www folder, using the service “media_player.play_media”, and passing it the complete URL to the mp3 file, but when I type something into the “Say” input on the lovelace card, the speaker clicks like it turned on but it doesn’t say anything.
The mp3 file from the text is being generated correctly and placed in the config/tts folder, I can listen to it from another computer through the samba share.
I think the problem is that the URL being sent to the media players does not point to the right location of the mp3 file, or that the config/tts folder is not being shared correctly on the web.
Question: Is there any way to see what URL is being sent to the media players to help troubleshoot this problem?

I’m using Sonos speakers, with media control cards in Lovelace. When a notification is played the file name appears in the Lovelace card - not sure if it’s the whole URL though, it disappears quite quickly.

Thanks,
I saw that but it only shows the file name, and it shows the proper file name for the mp3 of the text typed, so I know the TTS part is working corectly.
I can do a quick copy and paste of the file displayed, but it doesn’t show the full URL, which is what I need to troubleshoot.

Did you try looking in Developer Tools?

Where in the Developer Tools will it show the URL being sent to the media players?

In the attributes of the entity.