Hello maddep22,
If you are attempting to download your photos through the Photos or iCloud for Windows apps, you'll want to use the steps below:
How to download photos and videos from the Photos app
If you want to download a full-size copy of your photos and videos from the Photos app to your iPhone, iPad or iPod touch with iOS 10.3 or later or iPadOS, or your Mac with OS X Yosemite 10.10.3 or later, follow these steps.
On your iPhone, iPad, or iPod touch
1. Go to Settings > [your name].
2. Tap iCloud, then tap Photos.
3. Select Download and Keep Originals.
On your Mac
1. Open the Photos app.
2. Choose Photos > Preferences.
3. Select iCloud, then click Download Originals to this Mac.
On your PC
If you're using a PC, you can set up iCloud for Windows and download a copy of your photos and videos from iCloud Photos.
If you are instead trying to download your photos using the iCloud website, you'll want to follow the steps below:
How to download photos and videos from iCloud.com
If you want to save copies of your photos and videos from iCloud.com to your iPhone, iPad, iPod touch, or your Mac or PC, follow these steps.
On your iPhone, iPad, or iPod touch
1. On iCloud.com, tap Photos.
2. Tap Select, then tap a photo or video. To select multiple photos or videos, tap more than one. To select your entire library, tap Select All.
3. Tap the more button
.
4. Choose Download, then tap Download to confirm.
If your photos download as a ZIP archive, learn how to uncompress the folder on your iPhone, iPad, or iPod touch.
On your Mac or PC
1. On iCloud.com, click Photos and select a photo or video. Hold the command key on your Mac or control key on your PC to select multiple photos or videos.
2. Click and hold the download button
in the upper corner of the window. If you want to download your photo or video as it was originally captured or imported, choose Unmodified Original. For JPEG or H.264 format — including edits, and even if it was originally in HEIF or HEVC format — choose Most Compatible.*
3. Click Download.
If your photos download as a ZIP archive, learn how to uncompress the folder on your Mac or your PC.
You can also find those steps in this resource: Download iCloud photos and videos - Apple Support
Should you still be unable to download your photos or videos, do you receive a particular error message or prompt. As a reminder, make sure not to share any verification codes you receive.
We'll keep moving forward from there.