Is there a way to specify which ssh key should be used for npm install

Here are a few solutions:

• Add an entry to your ~/.ssh/config. For example:

  Host bitbucket.org
       IdentityFile ~/.ssh/bitbucket_key
       IdentitiesOnly yes
  

• Use ssh-agent and add your key to the agent instance beforehand.

• Use something like ssh-ident for choosing ssh agents and identities dynamically based on the current working directory or arguments passed to ssh-ident. As their readme states, you would typically alias ssh-ident to ssh so that it’s automatically used everywhere.