If you want to make your files and folders unaccessible outside of Lift File Manager by browser follow these steps below:
1- Go to the directory ../filemanager_assets by your ftp or host panel and find a file named htaccess.txt
2- Open htaccess.txt and edit it according to your needs
Here you should add those file extensions that you don't want to be accessible by browser.
We have added some file extensions as default. You should add your own.
3- After you amended the file htaccess.txt, copy it to your root directory where you have installed Lift File Manager
4- Rename the mentioned file from htaccess.txt to .htaccess
Now you're done and the files or folders you've defined are no longer accessible from the public by any browsers even if they know direct URLs.
NOTE: If you want to do the same thing with a specific directory on your server, place a .htaccess file in related directory .