SQL Server Enable filestream without having SQL Server Configuration Manager(so via command line only)
Regedit

You could change the registry settings for the instance's filestream settings.
Below is an example with the master..xp_regwrite procedure.

If filestream is disabled for the instance this shows:



The same is true when viewing with the configuration manager:





Via SSMS / SQLCMD / ...

As a result, you can change the EnableLevel value for the Filestream registry key. Remember to change MSSQL14.MSSQLSERVER in the example below to your sql server instance.

EXEC master..xp_regwrite
'HKEY_LOCAL_MACHINE',
'SOFTWARE\Microsoft\Microsoft SQL Server\MSSQL14.MSSQLSERVER\MSSQLServer\Filestream',
'EnableLevel',
'REG_DWORD',
3


This changes the value to full filestream access:



This can be validated with the configuration manager:



As always, change the registry at your own risk. Taking a backup of the registry is also a good idea.

After changing these settings, you would have to restart your sql server instance and configure the filestream_access_level .



Extra info

Level 2:

EXEC master..xp_regwrite
'HKEY_LOCAL_MACHINE',
'SOFTWARE\Microsoft\Microsoft SQL Server\MSSQL14.MSSQLSERVER\MSSQLServer\Filestream',
'EnableLevel',
'REG_DWORD',
2




And as expected, level 1:

EXEC master..xp_regwrite
'HKEY_LOCAL_MACHINE',
'SOFTWARE\Microsoft\Microsoft SQL Server\MSSQL14.MSSQLSERVER\MSSQLServer\Filestream',
'EnableLevel',
'REG_DWORD',
1