Error "Permission denied (publickey)" when installing Colyseus package with npm

[maxmonax]

Hi everyone,
I’m trying to install the colyseus package in my Node.js project using npm install colyseus, but I keep getting this error:

> npm i colyseus
npm error code 128
npm error An unknown git error occurred
npm error command git --no-replace-objects ls-remote ssh://[email protected]/uNetworking/uWebSockets.js.git
npm error [email protected]: Permission denied (publickey).
npm error fatal: Could not read from remote repository.
npm error
npm error Please make sure you have the correct access rights
npm error and the repository exists.

I tried this:

git config --global url."https://github.com/".insteadOf [email protected]:
git config --global url."https://github.com/".insteadOf ssh://[email protected]/

I have generated and added my SSH key to GitHub, and I can successfully connect to GitHub via SSH (ssh -T [email protected] works fine).
However, npm install still fails with the above error related to uWebSockets.js GitHub repo.
Has anyone encountered this issue before? How can I fix it?
Thanks in advance!