Ftp button on floating toolbar

I use a html editor with builtin FTP.
I use a css editor which hasn't.
So I thought DO to help me.
I build a dedicated button to ftp the particular css file I'm working on.

I created a button on a floating toolbar:

Copy "C:\my\path\to\screen.css" TO=@myftp WHENEXISTS=replace

But this command does not copy screen.css to myftp as long as the myftp is not selected DESTINATION. (Even when DO is not the current window, but my css editor)
It copies the screen.css to the directory in DESTINATION, whatever that is chosen.

What can I do better, to make the button always use the correct myftp site?

That works fine for me. It always copies to the FTP site regardless of the destination folder (or even if there isn't a destination folder at all).

Check you used the exact name of the site bookmark in your command. If the name contains spaces then you will need to put it in quotes.

(Note: I only tried with FTP, not SSH.)