Raspberry Pi setup for schema / NPM/NGROK

Goooooood morning Vietnam !!

I am willing to perform this tutorial but as most tutos this one is incomplete (for starting from scratch like me).

My questions are :

1/ I should install a raspbian on my RPI4 and then install npm and ngrok ?

2/ About the code, i will make it visual studio code app, like the tuto using the linux distribution.
Will running that command will be enough ?

3/ Does this command means node.js must be intalled ?

Thank you