fzf: ctlr-r not triggering history search on command line

I've installed fzf on debian 11 (bullseye). When I type in ctrl-r to trigger a history search, nothing happens. Works fine on my mac. I'm using zsh. UPDATE: tried adding bindkey '^r' fzf-history-widget to .zshrc but I just get a "no such widget" error. fzf --version reports 0.24 (devel)