Hey @ricou,
I'm sorry we couldn't get back to you earlier.
Did you get to run the Slice Machine init command? npx @slicemachine/ini@latest? If yes, it's weird it didn't install the Prismic module 
Can you try installing the Prismic Nuxt Module in your Nuxt config following this process: Get Started · Nuxt Prismic
Let me know if that solves your issue 