The users whose Private Chats are migrated automatically consumes the Licenses. But for the additional users, who are part of the chats, has to be assigned with licenses too, so that their chats are migrated.

To achieve this, navigate to Plan tab -> Reports -> Private Chat -> UnLicensed Users. Follow as in the below image to get the Licenses assigned.

Post this, you can migrate the licensed users chats as many times as you want.

Note: If your licenses are exhausted, please contact sales@apps4.pro to purchase additional licenses.