Pseudo-terminal will not be allocated because stdin is not a terminal

Also with option -T from manual

Disable pseudo-tty allocation


Try ssh -t -t(or ssh -tt for short) to force pseudo-tty allocation even if stdin isn't a terminal.

See also: Terminating SSH session executed by bash script

From ssh manpage:

-T      Disable pseudo-tty allocation.

-t      Force pseudo-tty allocation.  This can be used to execute arbitrary 
        screen-based programs on a remote machine, which can be very useful,
        e.g. when implementing menu services.  Multiple -t options force tty
        allocation, even if ssh has no local tty.