Txt checker

Hello.

I need a simple script, which can be done in php or ajax.
I have a text file, which is updated whenever a link is accessed.
When this link is accessed, it writes in the txt some information as date, time, link and result:

Below is OUTPUT (txt file):

28/06/21 - 13:08:27: Link [http://xxxx.com/f.php?ade=2253&deve=9629&dig=6]: {"nome":"MATHEUS","titulares":[],"exclusive":false,"prime":false}
28/06/21 - 13:09:51: Link [http://xxxx.com/f.php?ade=5213&deve=39847&dig=0]: {"nome":"","titulares":[],"exclusive":false,"prime":false}
28/06/21 - 13:10:29: Link [http:///xxx9xxx.com/f.php?ade=1537&deve=11354&dig=9]: {"nome":"RAFAEL","titulares":[],"exclusive":false,"prime":false}
28/06/21 - 13:10:38: Link [http:///xxx9xxx.com/f.php?ade=5502&deve=9410903362&dig=6]: {"nome":"","titulares":[],"exclusive":false,"prime":false}
28/06/21 - 13:39:34: Link [http://xxxx7xxx.com/f.php?ade=584&deve=319753&dig=0]: {"nome":"MARA","titulares":[],"exclusive":true,"prime":false}

Notice that sometimes in the variable `nome`, you do not return anything, right?
I need exactly the following:

That a file is constantly checking if the log.txt has changed, and if it was, check if a `nome` contains a name.
Valid example: {"nome":"MARA","titulares":[],"exclusive":true,"prime":false}

And if it is verified that there is a name, play a sound audio.mp3

If the txt updated and received this line -> {"nome":"","titulares":[],"exclusive":false,"prime":false}
Dont play sound!

If received this line -> {"nome":"MARA","titulares":[],"exclusive":true,"prime":false}
Play sound!