How to transfer photos and videos from iPhone to an external hard drive?

YOu missed this part about import in the link?

Import to your PC

You can import photos to your PC by connecting your device to your computer and using Windows Photos app:

1. Make sure that you have the latest version of iTunes on your PC. Importing photos to your PC requires iTunes 12.5.1 or later.
2. Connect your iPhone, iPad, or iPod touch to your PC with a USB cable.
3. You might need to unlock your iOS device using your passcode.
4. You might also see a prompt on the iOS device asking you to Trust This Computer. Tap Trust or Allow to continue.

Then, follow the steps in these Microsoft knowledge base articles to learn how to import photos to Windows Photos app:

• Windows 10
• Windows 8
• Windows 7

When you import videos from your iOS device to your PC, some might be rotated incorrectly in Windows Photos app. You can add these videos to iTunes to play them in the correct orientation.

If you have iCloud Photos turned on, you need to download the original, full resolution versions of your photos to your iPhone before you import to your PC. Find out how.

Photos and videos that you sync from your computer to your iOS device using iTunes can't be imported back to your computer. 

Learn what to do if you can't import photos from your iPhone, iPad, or iPod touch to your computer.

You cant get them from iPhone to an external drive directly. That might work from an iPad (see Here and then share to external drive), but not from iPhone directly to external drive.

So what razmee suggested might be the only option you have - import your files to a Computer and then from the Computer to external drive (or you can import them to the external drive directly) - but you need a Computer anyway.

Sam

you import them to your computer - then copy and paste it to external hard drive.

import Transfer photos and videos from your iPhone, iPad, or iPod touch - Apple Support

Mac -- export them with Image Capture (native macOS app) to the external drive with export option (drag&drop was working as well).

Win -- connect via USB and drag&drop from DCIM folder.

If you are asking about direct transfer -- no native way. There should be some third-party app in theory but haven't seen anything like this... There's a tedious way to do this with WebDAV connection through Files app to a NAS, but not sure if Files can connect to an external drive through USB > Lightning dongle.

Hope this helps.

Have you tried exporting photos separately from videos? There's currently some bug with transferring 4k/1080 videos to computer on both Mac and Win, haven't seen any workaround. It's not conversion as changing export to "Keep originals" won't help. Get iMazing if you won't find anything, never had any issues with file transfer. You can drag&drop directly to a folder on external drive and it has sorting options.

p.s. Could have misread your last post. If they are in iCloud full-res versions could be offloaded. Make sure that you have enough local space, change to "Download and keep originals" under iCloud Photo Library in Settings > Photos, then leave your phone charging overnight with a good Wi-Fi connection and not on battery saver mode.

Any thoughts?

Are these photos also in your Mac's photo Library being synced to iCloud? Are you optimizing them?