This TSplus documentation indicates how to perform a backup : https://docs.dl-files.com/tsplus/server-management
However TSplus can't backup the windows users and groups you have created.
TSplus will only backup Web Credentials and application assignation.
To migrate Windows accounts, we recommend using CopyRight2.
Web Credentials are backed up, and the information is located in these hidden files: webcredentials.ini and webcredentials1.ini.
Published Applications and Assignments are also backed up, and the information is located in this file: Appcontrol.ini.
Before applying the restore, you may need to modify the AppControl.ini file.
Indeed, if the server has a different name: it will be necessary to modify the assignment of the accounts <name-old-server-server> / ACCOUNT by <name-new-server> / ACCOUNT at the level of each of the deployed applications.
A "Search / Replace" can do this quickly!