Can't Download Any File from file manager

[hf_world]

My website URL is:
hfworld.ooo

What I’m seeing is:
It shows Download failed…I also tried with ftp but didn’t work…also used plugin…not working…I can’t download the backup file also…
See this screenshot: Screenshot-2019-05-09-23-58-44-899-com-android-chrome hosted at ImgBB — ImgBB

I’m using this software:
WordPress

FTP & web browser

Additional information:

[hf_world]

@Admin please help me…

[Admin]

I’m sorry, but I can’t fix some random online file manager you’re using. Can you please try to download the file either through one of our web based file managers, or a recommended desktop FTP client like FileZilla?

[Oxy]

I believe that the download is also limited in that onlineftp tool from user image

The only thing that confuses me did the user tried with monstaFTP or some other FTP
(which is not quite clear from his words)