Hello Astur,
NAV license will not work here , as you said you using BC v.16 so for that you have to login businesscenter.mbs.microsoft.com/ with the partner account and download the license from there by configuring it and import in Business Central database by some commands in BC administration shell (open it as admin)-
PS C:\Windows\system32> Import-NAVServerLicense
cmdlet Import-NAVServerLicense at command pipeline position 1
Supply values for the following parameters:
LicenseFile: give the path of your flf file
ServerInstance: mention your instance name
Also donot forget to restart the instance again.
Hope this helps
Thanks