For each job you create in LSP.expert, you can upload files from Dropbox, Google Drive and your computer.
In the job, you have a Files tab (on the left).
To add a file, click on 'Select file...'.
Note that LSP.expert will never overwrite any file, so if you upload a new version of a file, the system will always keep a trace of the old one.
The File Manager allows you to quickly find the files you're looking for, to keep track of all the files (old and new versions) for a job and to access these files from anywhere, on any device.