php acting weird in wordpress plugin

hello people im using an free wordpress plugin called WP Greetbox.
and in the area that I write my own greeting message I tried to execute some php

<?php 
$test = 'test';
echo $test;
?>

PHP:

but it dosent work???
when I check the source of the page after I see

<!--?php 
$test = 'test';
echo $test;
?-->

PHP:

Can someone help please

 

The plugin is deactivating PHP code by commenting it out. In other words, the plugin isn't allowing you to use PHP code where it's asking for plain content.

 

is there a way that I can enable it ???

 

Is the plugin compatible with your version of WP?

 

If not a setting you can edit the plugin. Search for where the code is looking for "<?" or "<?php" to replace it with "<!--" and just edit it out.

 

there is 4 php files in this plugin
There is no <!--

Check the attchmnet
I sent the 4 files

and @Blue Star Ent. yes this plugin is compatible with my WP version

 

I'm not going to go through the files. But I'm telling you if you are writing "<?php" from a text box and it's being converted in to "<!--php" obviously the script is converting the tag. It's either the script that displays the text or the script you submit the text to.

 

yes I understand and still can't find it.