Symfony with Svelte config doesn't generate package.json

I'm currently trying to set up a Symfony project and add Svelte to the project. On their website they claim that it's easy to add Svelte UX to the project.

I have the Symfony server running, but the node package manager can't install since there is no package.json file in the project root being generated. I ran this command:

composer require symfony/asset-mapper \    symfony/stimulus-bundle symfony/ux-svelte

The documentation says that I should then run npm install --force and after that I could run npm run watch.

But npm install doesn't have a package.json file to run from. Should the node project be set up manually, or should the composer require command set it up for me?