Application Language Error in Form Application

Hi,

I have an index in my application language that is used to show confirmation message.

index:
lang_confirm

value:
Click OK to confirm

Then I have forms where in their application messages for insertion, update and delete, the confirmation message is supposed be shown.
The form applications can be generated without error. However, when accessing the form apps, this error shows:

Parse error: syntax error, unexpected ‘$this’ (T_VARIABLE) in /Applications/Scriptcase/v9-php73/wwwroot/scriptcase/app/my_project/form_menu/form_menu_js0.php on line 242

Upon checking the php file, this is the line being referred:

if (confirm ("<?php
echo
$this->Ini->Nm_lang[‘lang_confirm’]
?>"))

This used to work before php7.3 update