My phone has used 66.5 gb of 256 gb

Hello farshaun,

Welcome to Apple Support Communities. We understand that you’re being prompted to add storage.

It sounds like your iCloud storage is low. 

Please use the steps here to manage iCloud storage: Manage your iCloud storage - Apple Support

"Make more space available in iCloud

If you run out of iCloud storage, your device won’t back up to iCloud, new photos and videos won't upload to iCloud Photos, and iCloud Drive and other iCloud apps won't stay up to date across your devices. And you also won't be able to send or receive emails with your iCloud email address.

You can free up storage in iCloud by deleting content that you're not using:

• Check Recommended for You
• Reduce the size of your iCloud Backup
• Delete photos in iCloud Photos
• Delete folders or files in iCloud Drive
• Delete texts and attachments in Messages
• Delete messages and manage Mail
• Delete voice memos

Before you delete anything, you might want to archive or make copies of the information that you store in iCloud.

Check Recommended for You

If you're getting low on storage in iOS 17 or iPadOS 17 or later, you can go to Recommended for You in your iCloud settings and check if there are photos, large files, or backups that you might not need anymore and can delete. 

1. Go to Settings > [your name] > iCloud.
2. Tap Recommended for You, then tap one of the options below and follow the onscreen instructions:

• Tap Review Backups to identify and delete backups from devices that you no longer use.
• Tap Review Photos & Videos to delete duplicate photos, screenshots, or videos that you might not need anymore. 
• Tap Review Large Files to get space back by deleting large files that you might not need anymore.

3. If you don't see any of these options, you can still manually delete content from iCloud." 

Here’s information on the difference between device storage and iCloud storage: What's the difference between device storage and iCloud storage? - Apple Support

"Device storage

An Apple device like an iPhone, iPad, or Mac comes with a set amount of storage. The more storage your device has, the more music, apps, photos, and other content you can store on that device. If your device storage is almost full or full, you might get an alert.

Here's how to check the amount of device storage you've used and, if needed, how to optimize and manage your storage space.

iCloud storage

To access your content on any device and help optimize your storage, you can also use iCloud storage. You can use iCloud storage to keep photos, videos, device backups, and more, and keep this content up-to-date across your devices. When your iCloud storage is almost full or full, you might get an alert and you can buy more.

If you want to free up iCloud storage space:

• Learn how to make more iCloud storage space available
• Learn how to get more iCloud storage"

These steps may help. Please let us know if you have further questions.

Take care.