Android: open the console in Chrome, menu › Install app (once). Then in WhatsApp / Viber: Share › Aasandha.
iPhone (once): make your key, then in the Shortcuts app make a shortcut:
Shortcut details (ⓘ): turn on Show in Share Sheet, accepts Images.
Add Get Contents of URL: URL below, Method POST, Headers: X-Share-Key = your key, Request Body Form: field file = Shortcut Input (File).
Add Get Dictionary Value: key url.
Add Open URLs. Name it "Check in Console".
The photo goes only to the office PC, is read like any prescription photo and is deleted once opened (or after 30 minutes). Making a new key stops the old one.