Question nodejs ssh dependencies key not work

[fjubuu]

My nodejs applikation contains inside the package.json a "ssh+git" dependencie and npm install cant get access to this repository.

git+ssh://[email protected]/xxx/zzz.git

In the File-Manager "/home_directory/.ssh" i installed the private key but it does not work.
Is there a another location i have to install the key?

In my desktop envoirment it works fine.