Google Docs can't be fetched directly from the browser, but importing is still easy:

Option 1 — Paste text: Open the doc, select all (⌘A / Ctrl+A), copy, then switch to the Paste text tab and paste.

Option 2 — Export as PDF: In your doc, File → Download → PDF, then upload that file on the File upload tab.

Option 3 — Export as text: File → Download → Plain text (.txt), then upload on the File upload tab.