playlist add elements and execute the last element

Hello.

With this

Code:
            url='http://'+ip_sel+':'+puerto_sel+'/jsonrpc?request=    {"jsonrpc":"2.0","id":1,"method":"Playlist.Add","params":{"playlistid":1,"item":{"file":"/home/osmc/Movies/'+flashmo_tn_list[next_pic_no].filename+'"}}}';

I add a element in the playlist of video, but not play the element. And when execute the second example clean all the list.

Code:
            url='http://'+ip_sel+':'+puerto_sel+'/jsonrpc?request={"jsonrpc":"2.0","id":"1","method":"Player.Open","params":{"item":{"file":"/home/osmc/Movies/'+flashmo_tn_list[next_pic_no].filename+'"}}}';

I will like insert element and after that play that element the last one.

Thank you