Basically, plugins on FreeNAS use the 11.3-RELEASE, which past EOL in October. I had to pull Node-RED and most of my other plugins from FreeNAS because I can not support the various issues trying to use an expired release has caused.
On FreeNAS, you should manually create a 11.4-RELEASE jail and install Node-RED as shown in the link above.
Node-RED is still available on TrueNAS Core, which is currently using the 12.2-RELEASE for plugins.