The code you've provided appears to be an HTML page with JavaScript that attempts to generate a PDF report using the jsreport library. Based on the code you've shared, here are a few things to check and consider:

jsreport Configuration: Ensure that you have properly configured the jsreport.serverUrl variable with the correct URL of your jsreport server. The URL should point to the jsreport server API endpoint.

Authentication: You mentioned the need for authentication to access the report. If your jsreport server requires authentication, you should handle authentication either through the server itself (using authentication plugins or middleware) or by sending authentication credentials (e.g., API keys or tokens) along with your API request. Make sure your server is set up to authenticate requests properly.

Template Name: The code specifies a template name 'TimeSheet'. You should make sure that a template with this name exists in your jsreport server. Templates in jsreport are used to define the structure and layout of the generated reports. Ensure that the template name is correct and that it matches an existing template on your jsreport server.

jsreport.render: The jsreport.render function is used to render the report. Ensure that the generateReport function is being called when you click the "Get PDF Report" button. You can add console.log statements or use browser developer tools to check if the function is being triggered and if any errors are being logged in the console.

HTML Structure: Ensure that the HTML structure is valid. The generateReport function seems to be using $("#placeholder") to target a <div> element with the id "placeholder" to render the report. Make sure this <div> element exists on your page.

JavaScript Errors: Check your browser's developer console for any JavaScript errors. Any errors in your JavaScript code can prevent the report from being generated.

Cross-Origin Requests: If your jsreport server is hosted on a different domain or subdomain, you might encounter cross-origin issues. Make sure that your server allows cross-origin requests from the subdomain where this code is hosted. You may need to configure CORS (Cross-Origin Resource Sharing) settings on your jsreport server.

Network Requests: Use your browser's network tab in the developer tools to inspect the network requests being made when you click the button. Check if the API request to the jsreport server is being sent and if there are any error responses.