To chime in: see our updated Installing and Using NodeJS documentation article for instructions on installing Node and npm v8.10
@Yvan-Gagnon can you please add [resolved] to the post title?
for anybody looking for the solution to installing blynk-library, the instructions in the blog post have been updated.
as per this other post on the subject.
In a nutshell, blynk-library can now be installed using npm.