How to change the scan filename in the Web BrowserNX sample application?

There are three job modes in the scanner job API.

1.scan_and_store_temporary - 

2.scan_and_send - ricoh.dapi.app.scanner.start() parameter "uploadOptions" has file name. You can change the file name by this API.

3.scan_and_store_local - Regarding this job mode, the scanned image file is stored into local storage of MFP HDD.  Your app can access the scanned image file via storage service API. Then you can change the filename via storage service API.  Rename by /rws/service/storage/files/{File ID} and send by /rws/service/scanner/jobs job mode "send_stored_file"

JS does not provide a Storage service API, however a web app can call the web API directly.