I am using the universal version of Appeon Powerbuilder 2017.

The Powerserver documentation ("FAQ & Workarounds - What files will go to the plugin folder...") states "For each Appeon application, a "plugin" folder will be created automatically under the application directory (so called sandbox on the mobile device and so called cache directory on the Web client) to store any external files created or used by the application"

When I run the following code in a mobile app the program displays a message that the file exists.  But, the file is not in the application's plugin directory on the server.  How can a mobile app write to a file in a directory on the server?  

int li_fileid
int li_rc
string ls_file = 'Testfile.txt'
li_fileid = fileopen (ls_file, linemode!, write!)
li_rc = FileWrite (li_fileid, 'This is a test')
fileclose(li_fileid)
if fileexists(ls_file) then
    messagebox(ls_file, 'file exists')
else
    messagebox(ls_file, 'file does not exist')
end if