Can't Activate

Is the WHMCS Provisioning plugin required to use WHMCS WP Integration plugin? When trying to activate the plugin, I get the following message:

Plugin could not be activated because it triggered a fatal error.
Parse error: syntax error, unexpected T_FUNCTION in /******/*******/******/wp-content/plugins/whmcs-wordpresss-integration/whmcs-integration.php on line 811

I should point out that as per WHMCS' security recommendations, /whmcs is not my installation folder and /whmcs/admin is not my admin dashboard. Do these variables need to be changed somewhere in the code for the plugin to work?