Some programs or scripts may require you to give files or folders specific permissions in order for them to work.
To do this with FileZilla, simply right-click the remote file or folder and choose the “file permissions” option. Set the numerical permissions specified by the program writers and click “OK”.
If you use a different FTP programme, consult the help section of your software.
Or you can change file and folder permissions by using the file manager found in your hosting cPanel.