You can add any custom log file from you web site directory to track its changes in the Log Browser.
To add a Custom Log File, perform the following steps:
1 – Logged in to Plesk.
2 – Go to Websites & Domains.
3 – Click on Logs.
4 – Click on Manage log files, from drop menu in the top right side.
5 – Click the Add Custom Log button on the Manage Log Files page.
6 – The tree with your web site folders will be displayed. Select the file that you want to add to the Log Browser and click OK.