PHP 7.4 update showing notices on the plugin

I like the Timetable plugin, I use it often on the sites I work on, but after the PHP update to 7.4 WordPress shows the following notice (when turned on the dev server):

Notice: Deprecated: Array and string offset access syntax with curly braces is deprecated in /wp-content/plugins/mp-timetable/classes/libs/FirePHPCore/FirePHP.class.php on line 1327

Actually, many other lines like this, but this one is just an example.

I’m not sure whether you’ve been familiar with this, but this issue might arise every now and then on the sites I’m working on. I’d like to know whether an update is planned to have this sorted out or not.

Thanks and all the best!