Here is what you have to do.
Open your m3u file with a text editor. If there is only one line which ends with "m3u?t=3", then copy the line and then ftp your box. go to:
/etc/tsmedia
find the file called "TSmedia_iptvlist". Open it and paste the line you just copied into it starting with "m3u,;".
Example:
m3u,;Myline-------------------------------------------/playlist.m3u?t=3
Save and exit

.
Good luck