Uploaded documents online, but do they need to be mailed too?

Apologies if this has previously been addressed, newbie on here needing some advice from anyone that has submitted through the VFS Global system.

My partner (US) has completed her online application for a Marriage Visitor Visa, and opted to upload all the required supporting documentation instead of paying for the scanning services.

She attended her biometrics appointment today at a Visa Support Centre in FL, and has her stamped appointment booking.

We are both some what perplexed.. 
Reading different things on various places and the VFS site confusing me as well..

Seeing as the documents have already been uploaded, what needs to be mailed to the UKVI Scanning Hub (NY)?

Thanks in advance, appreciate any advice.

I'm not sure about the requirements for a marriage visitor visa, but for settlement visas like a fiance visa or a spouse visa you still send your passport and stamped biometric appointment sheet to the scanning hub even if the supporting documents are all scanned in online. They need the passport to put the vignette sticker in for the visa.

Thank you for the response! Appreciate it so much. 

My partner is ready to mail her application today, and after weeks of getting everything ready we don’t want to stumble at the final hurdle.

So to be crystal clear, what my partner needs to mail to the NY processing hub is just:

- passport
- biometric app sheet

Is that it?

So to be crystal clear, what my partner needs to mail to the NY processing hub is just:

- passport
- biometric app sheet

Is that it?

You need to mail:
- Passport
- Stamped Biometrics appointment sheet
- Printed online application... though I think just the first page with the barcode is required now?
- Priority processing receipt (if paying for priority)
- Return shipping label
- Return envelope

Also see here for how to apply in the USA, as it has instructions for mailing etc.:
https://www.gov.uk/government/publications/usa-apply-for-a-uk-visa/apply-for-a-uk-visa-in-the-usa