I’m digging into this too. Actually there is no need to install localforage. Like @rapropos said, LocalStorage uses LocalForage.
I imported Storage from @ionic/storage and used the same way you are using localforage, but the syntax is a bit different. Instead of:
localforage.setItem('key', 'value' );
use:
storage.set('key', 'value');
The same for getItem and get.