Cloud
Hand a folder to a gallery.
If you also run GalleryID Cloud, Desktop can upload straight into it. Everything else about Desktop is unchanged: this is a door, not a requirement.
Open View → Cloud and sign in. This is a different login from your Desktop license. It has to be, because the two answer different questions: the license says this computer may run Desktop, and the Cloud sign-in says which account you are uploading to. Signing out of Cloud does not touch your license.
That separation is the useful part when you work for more than one organization. Sign in to a client’s account, send their game, and switch back. If your login belongs to several accounts, a dropdown in the Cloud header switches between them without signing out.
Sending
Send to Cloud…
Select photos in Browse, then File → Send to Cloud… or the right-click. Pick a destination gallery from the tree, or type a title and create one on the spot. With a RAW and JPEG pair selected you choose which half travels, the same way an export does.
MatchID on upload
Off by default, and that is deliberate
Photos leaving Browse have usually been tagged and reviewed on your own machine already, so running recognition again on the Cloud side would be work you have done. Tick Run MatchID on these photos when the upload is raw material rather than finished work. The pill beside Upload photos… on the Cloud page does the same job for uploads started there, and it re-arms itself to off after each send.
A new gallery is Private until you say otherwise. The Send to Cloud dialog offers Private or Public while you are typing a new title. If setting it Public fails for any reason, the gallery is still created and stays Private, and the message tells you so rather than leaving you guessing which way it landed.
Share links are made from the Share button on a gallery: optionally a password, an expiry date, and whether the recipient can download. That gives a client a view-only URL without an account.
Your crops and edits can be applied on the way up, so the gallery copy is the delivered look rather than the untouched frame.
Switching accounts inside the Send dialog puts you back on the account you started from when the dialog closes. Switch, send, switch back, without losing your place.