PHP 7.4 Warning Messages

I have just upgraded out test server to PHP 7.4 & Ubuntu 20.04 LTS.

Running the WordPress File Upload Pro plugin, Version 4.12.2.

I now get these warning messages in my error log:

<b>Deprecated</b>:  Array and string offset access syntax with curly braces is deprecated in <b>/var/www/html/wp-content/plugins/wordpress-file-upload-pro/lib/wfu_security.php</b> on line <b>89</b><br />
<br />
<b>Deprecated</b>:  Array and string offset access syntax with curly braces is deprecated in <b>/var/www/html/wp-content/plugins/wordpress-file-upload-pro/lib/wfu_functions.php</b> on line <b>363</b><br />
<br />
<b>Deprecated</b>:  Array and string offset access syntax with curly braces is deprecated in <b>/var/www/html/wp-content/plugins/wordpress-file-upload-pro/lib/wfu_functions.php</b> on line <b>366</b><br />
<br />