How do I delete my photos from iCloud?

Hello,

If you are looking to delete all of your photos at once I recommend the iCloud.com option as it will be easier to select and delete them all at once.

Manage your iCloud storage - Apple Support

"Delete photos in iCloud Photos

iCloud Photos uses your iCloud storage to keep all of your photos and videos up to date across your devices. You can make more space in iCloud when you delete photos and videos that you no longer need from the Photos app on any of your devices.

Before you delete anything, make sure that you back up the photos and videos that you still want. When you use iCloud Photos and delete a photo or video on one device, it's also deleted on all other devices where you're signed in with the same Apple ID.

Use the steps below to delete photos and videos from your iCloud Photos. If you don't use iCloud Photos, you can delete photos from your Camera Roll instead.

If you are part of an iCloud Shared Photo Library, photos added to the Shared Library only count towards the storage of the person who created the Shared Library. To delete items that count towards your iCloud storage, make sure that you're viewing your Personal Library."

...

"iCloud.com

1. From your iPhone, iPad, or computer, sign in to iCloud.com.
2. Select the Photos app.
3. Select the photos or videos that you want to delete. 

• • To select multiple photos or videos, tap Select on iOS or iPadOS, or press and hold Command on a Mac or Control on a PC while you select the items.
  • To select all, press and hold Command-A on macOS or Control-A on Windows, or tap Select All on iOS or iPadOS. 

1. Tap Delete , then tap Delete.

You can recover photos and videos that you delete from your Recently Deleted album for 30 days. If you want to remove content from Recently Deleted album faster, tap Select, then select the items you want to remove. Tap Delete > Delete. If you exceed your iCloud storage limit, your device immediately removes any photos and videos you delete and they won't be available for recovery in your Recently Deleted album."

I hope this helps.