How can I recover deleted messages?

So sorry you have lost messages.

So the only way to recover lost text messages would be restoring from a backup if you do not currently use messages in iCloud.

IF you have a iCloud backup messages would not be saved in a backup since they would be syncing to your iCloud. https://support.apple.com/en-us/HT207428 - When you use Messages in iCloud or turn on iCloud Photos, your content is automatically stored in iCloud. That means that they're not included in your iCloud Backup.

Please remember anything that is deleted from the iCloud deletes from all devices.

You could also try to restore from a backup that you made on your Mac or PC.

If none of those options work for you, there is no way to recover those deleted messages.

hope this helps ;)

I needed to retrieve some lost messages

and did you go thru the Apple Recommended response of the thread you posted in? it should answer your question