For a particular case in a Vue.js and JavaScript project a NPM package dependency have to be merge with the current JavaScript code base.

In that specific case, the NPM package should not be part of the nodes_modules folder anymore but rather be part of the JavaScript code itself.

In that case as both codebases will grow together in the future. (Independently from the original NPM package and not as a Fork)

How can I merge or fusion a NPM package to a Javascript project?

Additional Details:

• The library that need to be merge is OIDC client. It's an open source project "Archived" by it's author (So no possibility to create Pull Request for a new release).
• It is use to create a SSO for an internal project. This library has been retain by architect the for specific need of the project and there is no other option than this one.
• There is no "internal package manager" available in this company
• I don't want to host the fork on my personal Github and manage the package on NPM website