Neither Goodreads nor StoryGraph allows a browser to read your account directly, so this reads their export files instead, nothing is uploaded and no login is involved.
GOODREADS
My Books → Import/Export → Export Library. Open the CSV, copy all, paste below.
STORYGRAPH
Manage Account → Export StoryGraph Library, then paste it the same way.
OR JUST TYPE
One title per line, and every line counts as read.