The message function in the AI cloud is not available because the ai cloud accounts and messages are different, how can I fix it?

“AI cloud”? Apple has no such structure in its ecosystem.

Perhaps you mean iCloud. I will assume that’s what you mean.

If so, there is a major issue here. You refer to what would correspond to “iCloud accounts”, which are actually governed by Apple IDs. So you are talking about multiple Apple IDs attempting to access the same messages.

Each person , regardless of age, needs her/his own, unique Apple ID. That Apple ID contains data, including messages, that are only accessible by that person (and, of course, the other sender or recipient).