On dropbox there is the possibility of requesting files by creating a link for sending.
There is someone who already has experience in sending files with this system automatically with a macro.
the link I generated for sending is:
https://www.dropbox.com/request/dA4PwiYqMIc9pXRN4vGf
I published the same post in the following forums:
vbaexpress
chandoo
ozgrid
excelguru
mrexcel
excelforum