for incoming webhooks I'd try to avoid having to expose your server to the Internet.
My solution would be to use an intermediate service like http://dweet.io/ that provides a webhook URL and translates that into a URL that can easily be queried at regular intervals.
It depends which way round you need the service to run.
if node-red needs to receive a message then IFTTT Webhooks needs a publicly accessible URL. But I agree, steer clear of exposing any ports on your server. In this case I'd use a service like http://dweet.io/ that can set up a free URL for IFTTT to access and another URL that node-red can monitor.
If you are trying to get node-red to trigger IFTTT to do something. Then belibeond is correct, you do not need to expose anything.