can't set export GPG_TTY=$(tty)

hi everyone
i have added export GPG_TTY=$(tty); eval $(gpg-agent --daemon)
to my .profile file
and also tried adding it to my .zshrc,
my window manager is I3,
when i open a terminal and and type env | grep GPG_TTY
i get GPG_TTY=not a tty,
if i run the export command in the terminal
then i get GPG_TTY=/dev/ttype3 .
where should i be putting the export command so that there is a tty
ready when the terminal is opened.
shadrock