Check that the portal accepts a single PDF and note the order it asks for. Lay the pages on a flat surface with even light. Keep the whole page in view, including corners, stamps and handwritten notes.
Prepare the file
On iPhone, open Files or Notes and look for Scan Documents. On Android, the Google Drive app has a scan option. Capture the first page and keep adding pages in the same scanning session. Review each crop before saving. If the page contains pale print, compare the color and grayscale previews.
Check the finished copy
Save the file using a name you can recognize in the portal. Open it from your file manager and swipe through all the pages. Check that none are doubled, sideways or missing. If the upload has a size cap, check the final PDF before attaching it.