I added the text to the site’s functions.php file, but received the error “Unable to communicate back with site to check for fatal errors, so the PHP change was reverted. You will need to upload your PHP file change by some other means, such as by using SFTP.”
I don’t really know where to start with writing a plugin. Any help would be appreciated.
If you have direct access via FTP or if your web hosting control panel offers some kind of file manager, perhaps you could create a new directory at wp-content/mu-plugins and then create a file called event-tickets-plus-customizations.php within that.
In that file, start with an opening PHP tag <?php on the first line then follow with the line of code I shared above on the next line, ie: