I think this is for when you are already added as a writer. For new requests, I think we need to send an unpublished draft link (as a pitch) via email.

I am not a 100% sure, but I believe this to be the case to the best of my understanding.

Once you are added as a writer to any publication, you can follow the method linked, by clicking on the three dots and submitting the draft.

Hope this helps.