1. Set CefSettings.RemoteDebuggingPort
/// <summary>
/// Set to a value between 1024 and 65535 to enable remote debugging on the
/// specified port. For example, if 8080 is specified the remote debugging URL
/// Chrome browser window.
/// </summary>
public int RemoteDebuggingPort { get; set; }
2. Get devtools url via CefBrowserHost:
/// <summary>
/// Returns the DevTools URL for this browser. If |http_scheme| is true the
/// returned URL will use the http scheme instead of the chrome-devtools
/// scheme. Remote debugging can be enabled by specifying the
/// "remote-debugging-port" command-line flag or by setting the
/// CefSettings.remote_debugging_port value. If remote debugging is not enabled
/// this method will return an empty string.
/// </summary>
public string GetDevToolsUrl(bool httpScheme)
3. Open this url in regular browser.