What came after that ? - It looks like a warning rather than an error... (so far)...
Basically it means it's an old node and about the break soon when they finally remove the os.tmpDir() function... and the packaging of the node could be improved with a more correct license clause... but as long as it's just a waring... it should be ok... (for now).
What version of npm are you using? Running npm install doesn't run any code in the module you are installing, so it would not have triggered the DeprecationWarning. The only running code is npm itself. So, the question is what version of npm and node are you using? What's the result of:
Thanks for all the help... still pretty new to python, node-red, Raspi... I'm using ESP32 with upython and MQTT to monitor some temps and control some outputs on the ESP32. I have some of the sonoff devices but have not modded any of them... are folks using the tasmota software on the sonoffs.