Drat, OK so you can see that all of the devices are owned by root/root which doesn't help you very much.
Here, for example, is the output on a Raspberry Pi
As you can see, ownership is root/gpio which means that you only need to add the userid that runs Node-RED to the
gpio group and it has access.
My recommendation is that you create a gpio group and reassign ownership something like this:
sudo groupadd gpio
sudo chown -R root:gpio /sys/class/gpio
sudo usermod -a -G gpio <userid>
<userid> with the userid that is running Node-RED. Sorry, not sure if you then have to log out and back in for the user to actually pick up the group (assuming you are logged in with the same account).
Also note that the
/sys/class/gpio actually are linked back to
/sys/devices and you will need to go and change ownership on those as well.
This avoids the need for you have to install and run Node-RED as root which is rather more secure. Also note though that you are opening up control of your GPIO ports to that user - you will want to make sure that you are using a decent password (or cert-based login) and make sure that if you are exposing Node-RED or other endpoints to the Internet that you have properly secured everything.