How to use plugin-proposal-private-methods in npm package?

Question

npm

I wrote a small lib for myself. It used babel plugins for private properties and methods. I install lib to the project via npm i username/git_repo_name. After importing I get an error.

In a project, babel-loader excludes the node_modules folder. In general, it seems clear what the error is and why it pops up, but it is not clear how to fix it. I'm trying to write a package for the first time, tell me at least what to google))