Ionic 2 angular-2-in-memory-web-api 404 error

I’ve been developing a simple app in Ionic 2 and I tried using mock service (in-memory web API) for fetching data as described in this Angular 2 tutorial. My console reported this error:

TypeScript error: app/app.ts(11,49): Error TS2307: Cannot find module ‘angular2-in-memory-web-api’.

I tried this solution: angular2-in-memory-web-api 404 error. After running this:npm i angular2-in-memory-web-api --save, I was unable to find the files where I was supposed to use the code provided in the rest of the solution.

How can I fix this? Sorry if the question is not posed quite right, this is my first one. Please ask if any additional information is needed. The problem is pretty much the same as the one for which the solution was provided in the link above, except that using Ionic 2 makes the given solution inapplicable in my case. I’m don’t think SystemJS is being used, please see my file structure image.