Rails importmap installs vendor scripts in vendor/javascript and expects me to check that directory into version control:

The packages are downloaded to vendor/javascript, which you can check into your source control, and they’ll be available through your application’s own asset pipeline serving.

But I don’t want to check those files in. I want to gitignore them, as you normally would with something like NPM and the node_modules directory, and instruct my production environment (Heroku) to install those dependencies itself. Ideally using something I can put in my Procfile.

How do I do that? There’s only one rake task, and that’s to install importmap itself, not the dependencies. I checked the commands too.

I could maybe cobble something together that iterates over the dependencies and downloads them individually, but normally package managers offer a pre-existing public API for this, so I’m sure I’m just missing something.