Files are uploaded from the Files tab of the record they belong to. The steps below use a job as the example, and they are the same on any record that has a Files tab.
Open the job and click the Files tab.

Open the folder you want the files to land in, then click New Files. Drag files or a whole folder into the drop area, or browse to select them.
Scroll to the bottom of the list and click Save.
A progress panel appears and stays visible while the upload runs. You can continue working elsewhere in Airstudio without interrupting it.

When every file has finished, the panel closes and the files appear in the Files tab.

ZIP archives are extracted automatically once they arrive. The progress panel tracks the extraction separately from the upload itself, so a large archive shows an upload stage followed by an extraction stage. The extracted files and folders appear in the destination folder, and the original archive is not left behind as clutter.
Large uploads survive interruptions. If a browser tab closes, a connection drops or a laptop sleeps mid transfer, returning to the same Files tab offers to resume.
The prompt reports how many files completed, how many can be resumed, and how many were cancelled. Choose Resume Upload to continue from where it stopped, or Abort to discard what remains. Files that already finished are not uploaded a second time.