Recover messages

Deleted messages are saved in iPhone backups. To recover them from a particular backup, use Restore your iPhone, iPad, or iPod touch from a backup - Apple Support

Apologies. I had tunnel vision when I posted before. I thought you were talking only about an iDevice and for some reason fixated of using a backup.

Also see: How to Recover Deleted Text Messages on Mac https://www.ibeesoft.com/recover-mac/recover-deleted-messages-imessages-mac.html

And here is more information related to iDevices: How to retrieve deleted text messages on iPhone https://www.macworld.co.uk/how-to/iphone/retrieve-deleted-texts-iphone-3636380/

If you were syncing Messages with iCloud and deleted them, they can't be recovered.