Starting backend projects and getting error before starting

I just started the backend challenges and am trying to do them on Cloud9. The first challenge is to install npm using the npm install -g how-to-npm command. I did that. Then you are supposed to verify that npm is installed by using the command how-to-npm verify. When I do that, I got a bunch of errors. Can anyone help me understand what’s going on?

OK, I got it working after finding this on Stack Overflow:

The command I used was nvm install 8.10.0 and then followed the instructions from the freecodecamp page, i.e., npm install -g how-to-npm and so on.

Copying the error I was getting before so if people have the same problem and search it on this forum they can find it: “Cannot find module ‘isarray’”