Stick table not working

In frontend

stick-table type ip size 2m expire 10m store http_req_rate(10m)
http-request track-sc0 src

and when I view the table it is empty.

echo "show table https-g9" | socat UNIX:/var/lib/haproxy/stats -
# table: https-g9, type: ip, size:102400, used:0

What am I doing wrong?