You can add any custom log file from you web site directory to track its changes in the Log Browser.
To do this, perform the following steps:
1 - 1 - Logged in to Plesk, https://your domain name:8443.
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.