Is there a way to request iMessage history from Apple?
Unless you store your iMessage data on iCloud (New feature introduced iOS 11.3), Apple does not directly store your iMessage data. There may be instances of iMessage data in iCloud Backup. This data can be extracted by various recovery programs, but not "requested" from Apple.

Even if you do store it on iCloud it is encrypted is not accessible in the fashion you are requesting it.

You can however request a copy of all the data Apple has.