iCloud

Hi there, meglam361!

Thanks for reaching out to the Apple Support Communities! It sounds like you're needing to connect your Messages with your iCloud account. If you're needing to set up your account to receive Messages across you're devices, you'll need to check out this article to Set up Messages on iPhone:

"Sign in to iMessage on your Mac and other Apple devices using the same Apple ID

If you sign in to iMessage with the same Apple ID on all your devices, all the messages that you send and receive on iPhone also appear on your other Apple devices. Send a message from whichever device is closest to you, or use Handoff to start a conversation on one device and continue it on another.

1. On your iPhone, iPad, or iPod touch, go to Settings  > Messages, then turn on iMessage.
2. On your Mac, open Messages, then do one of the following:

• • If you’re signing in for the first time, enter your Apple ID and password, then click Sign In.
  • If you signed in before and want to use a different Apple ID, choose Messages > Preferences, click iMessage, then click Sign Out.

With Continuity, all the SMS/MMS messages you send and receive on iPhone also appear on your other iOS devices and your Mac. See the Apple Support article Use Continuity to connect your Mac, iPhone, iPad, iPod touch, and Apple Watch."

If you're wanting to set up for your Messages to be saved to iCloud to be seen across your devices, check out this section:

"Use Messages in iCloud

Go to Settings  > [your name] > iCloud, then turn on Messages (if it’s not already turned on).

Every message you send and receive on your iPhone is saved in iCloud. And, when you sign in with the same Apple ID on a new device that also has Messages in iCloud turned on, all your conversations show up there automatically.

Because your messages and any attachments are stored in iCloud, you may have more free space on your iPhone when you need it. Message bubbles, whole conversations, and attachments you delete from iPhone are also deleted from your other Apple devices (iOS 11.4, iPadOS 13, macOS 10.13.5, or later) where Messages in iCloud is turned on.

See the Apple Support article Keep all your messages in iCloud.

Note: Messages in iCloud uses iCloud storage. See Manage Apple ID and iCloud settings on iPhone for information about iCloud storage."

If this is not the path you're needing to go, feel free to circle back with more information about your question.

Cheers!