Trying to use Material UI components, but import not working

I try to use code components (Material-UI), I’m following the instructions at https://docs.plasmic.app/learn/app-hosting/#scheme=loader&framework=nextjs . I’m actually using react router version 6 (so clicked on the related tab for the code example).

Compilation gives an error for line: import { PlasmicCanvasHost } from ‘@plasmicapp/loader-react’;
It can’t resolve @plasmicapp/loader-react.

I have synchronise my plasmic project with my React repo using plasmic sync -p .

I can see a plasmicapp folder in the node-modules folder but it doesn’t contain ‘loader-react’