Install package from private GitHub repository with yarn - App Platform static site build fails - permission denied

Hi, my site has a dependency which is a private GitHub repository like this:

In package.json:
...
"dependencies": {
  "library": "myusername/library",
  ...
},
...

I’ve authorized Digital Ocean to access all my repositories but during the build, the library package cannot be retrieved, erroring with:

git@github.com: Permission denied (publickey).
fatal: Could not read from remote repository.
Please make sure you have the correct access rights

What I’ve tried:

• using different ways of adding the package detailed at https://docs.npmjs.com/cli/v7/configuring-npm/package-json#git-urls-as-dependencies
• checking if there’s a GitHub token in the process.env that I could use
• adding an .npmrc (fails with yarn)
• looked through all the pages I could find
• many variations of all of above

---

What is the correct way of adding this library package dependency such that it can be fetched during build?

I’d really appreciate any help.

Thank!