npm library publish local

If you have made these changes on your machine. (I'm assuming you have)

Run a build of the package that you changed.

run npm pack from that package's root folder. This creates a .tgz zip file of your package with your custom modifications.

copy that file into the root (you could put it wherever but root makes things easy) of your project.

in your package.json replace the version number ngx mask to the following "your-package": "file:my-packed-file.tgz"

Run an npm install using your new package.json

you should have your modified copy loaded in as a dependency in node_modules.

https://stackoverflow.com/questions/55560791/build-and-use-npm-package-locally