Unable to backup Messages on my iCloud

Penelope1600 wrote:

I can’t put my iMessages on my iCloud

What exactly do you mean by that? If you're using iCloud Syncing for Messages, the messages are not part of your backup. And, whether your using iCloud Syncing or not, you cannot access the messages through iCloud.com.

Perhaps if you explain exactly what you're trying to do and what's happening, someone could provide useable advice.

To sync the messages to iCloud you have to enable them in settings/ iCloud/ messages in iCloud just make sure that iCloud has enough space available