A quick guide on how to export the RAW/DNG file from Adobe Lightroom CC on mobile and share them on DropBox.
Step 1 - Create a folder on Dropbox
Create a folder on Dropbox that you will upload the DNG files into from Lightroom.
Step 2 - Navigate to All Photos
Within Lightroom, click All Photos
Step 3 - Select image to export
From your All Photos album, click/select the image you would like to export
Step 4 - Select Export
Once you have opened the image you would like to export, click the 'Export' button top of the screen as circled below.
Step 5 - Export as
At the bottom of the menu, select 'Export as....'
Step 6 - Select 'Original'
Select the drop-down under 'File Type' and select 'Original' or 'DNG' from the menu.
Step 7 - Confirm
Select/click the tick top right of the screen
Step 8 - Save to Dropbox
Select Save to Dropbox from the menu and then navigate to and select the Dropbox folder you created in step 1 and click Save