bq78350 Cell Balancing Test

I want to activate the balancing FETs using the ManufacturerAccess() Cell Balance Toggle command (0x1b) (bq78350 TRM Section 16.2.12).
It requires ManufacturingStatus()[CBTEST] = 1.
That bit can be read using command 0x57 in a read-only register.  CB_TEST bit is at 0.

How can I write CB_TEST bit to 1?

In addition, do I need to only issue 0x1B command or it needs a parameter?  I feel it is only a command but what to make sure...

Cell balancing is enabled in Balancing Configuration Register.

Thanks,

Frederic