How can I view text messages from my ICloud?

Sorry, there is no option to do that. You cannot view the contents of an iCloud Backup -- you can only use it to do a full restore or to setup a new device. See: Restore your iPhone, iPad, or iPod touch from a backup - Apple Support

Also, if you have iCloud Messages turned on (that's different than iCloud Backup) see the following from Use Messages in iCloud - Apple Support

You can use Messages in iCloud on your iPhone, iPad, iPod touch, Apple Watch, and Mac. For your privacy, Messages in iCloud is end-to-end encrypted, which means you can't view or access Messages online via browser. 

"Texts I have backed up on my iCloud", if any, would require both the following:

• You use iCloud as your iOS backup method
• You do not use iCloud to house your text messages. (If you do house your messages in iCloud, they are not backed up.)

If both the above are true, then you would have to restore that iCloud backup to retrieve the text messages contained within it.

Restore your iPhone, iPad, or iPod touch from a backup - Apple Support

Please follow the following steps:

1. Open Settings on iPhone
2. Tap on your Apple ID (Your Name)
3. Tap on iCloud
4. Tap on Manage Storage
5. Tap on Messages
6. Tap on "Top Conversations"

From here you will be able to see which conversations are using the most storage within iCloud.

I hope this answers your question!

Ensure that iCloud for Messages has been set to ON. Open Settings ➡️ Apple ID (Your Name at top) ➡️ iCloud ➡️ Messages: Ensure that this is set to ON.

Note that your messages are not archived on iCloud but they are synced to iCloud. You should be able to see all of your messages in the Messages app by scrolling up/down. What you see in your Messages app is what is synced to iCloud.

Axel F.

From here you will be able to see which conversations are using the most storage within iCloud.

You can see which conversations are using the most storage......but you cannot actually see the content or text of the messages themselves.......which I believe is what the OP wanted to do.