Why can I not see the $ on my node app?

Hello!

I’m trying to instal Mocha on Node but it won’t let me even write the first command. There’s no $ sign when I open the app only the > sign and it won’t recognise the first command of npm init. When I type npm init it says:
“npm should be run outside of node.js REPL, in your normal shell.” What does this mean, please?

I’ve tried running the command in Node.js Command Prompt but I’m having issues there too. I should add that I’m on the following part of the full stack course:
Link to exercise