Tutorial "Build a shopify App" part 3 fails while following instructions

[ModestMonk]

https://developers.shopify.com/tutorials/build-a-shopify-app-with-node-and-react/embed-your-app-in-s...

I am following the tutorial and can not overcome step 3. After I complete everything, at the end of part 3 when I go to access my localhost I get the following error:

Expected a valid shop query parameter

To my knowledge I have everything entered exactly as described in the tutorial and can't figure out what is wrong by the message. 

[katiedavis · Accepted solution]

Hello @ModestMonk,

If you're seeing that in your browser, you'll need to pass the query param of your shop and authenticate your app, it's a bit further down in that step:

https://developers.shopify.com/tutorials/build-a-shopify-app-with-node-and-react/embed-your-app-in-s...

You won't be able to just head to your localhost url because the middleware in your server expects you to authenticate your app

[ModestMonk]

I was looking for the answer backwards, not forwards. I should have known, thank you.