Having trouble using/installing #pnp/sp modules - sharepoint-online

Question

I'm trying to use the attachments module, specifically these features:
https://pnp.github.io/pnpjs/sp/attachments/
I've installed all pnp/sp modules necessary (I think!) using : https://pnp.github.io/pnpjs/getting-started/ as a reference.
Problem is I'm getting a 'cannot find module' for the attachments module. Below are the imports:
import { default as pnp } from 'sp-pnp-js';
import { ItemAddResult, Web } from 'sp-pnp-js';
import { sp } from "#pnp/sp"; //this is fine, which suggests it's installed properly?
import { IItem } from '#pnp/sp/attachments'; //cannot find this module
import "#pnp/sp/webs";
import "#pnp/sp/lists/web";
import "#pnp/sp/items";
import "#pnp/sp/attachments";
I've been successfully using pnp.sp features in this particular project so am stumped why I can't import and use the attachments feature.

Answer 1

If this is an existing project, that you've had for a bit, and you've already got #pnp in the package.json file, it may be you're using version 1 of #pnp, and you are reading the documentation for version 2.
I get the same error cannot find module when I add it to a project #pnp/sp 1.3.7
But don't get it with version 2.0.0
Version 1 document for attachments:
https://pnp.github.io/pnpjs/v1/sp/docs/attachments/
Version 2:
https://pnp.github.io/pnpjs/sp/attachments/