You can purchase the server edition, which will enable you to log in and share the same installation…
The desktop version is single use only. But here are a few ideas you could try:
If you wish to ‘share’ the data between two desktop versions, you can backup: Make a backup of existing business and then restore: https://forum.manager.io/t/restore-from-backup/6263 the data file between them…
You could also try remote desktop in from the laptop to the PC and use the one installation.