error with wix-pricing-plans-backend API

Hi all
I am writing my first bit of Velo to improve the Subscriptions functionality on my site.
When I use the example from this tutorial I get an error on line 1 - not very hopeful!

import wixPricingPlansBackend from ‘wix-pricing-plans-backend’ ; // for managing plans

.eq(“primary”, false)
.then((results) => {
console.log( results.items );

This is the error I get in the browser console:

Cannot find module ‘wix-pricing-plans-backend’ in ‘public/pages/ui3tx.js’

BTW, I’m new to Velo, not to javascript and programming.

What am I doing wrong?