As forms aren't ready yet... you'll have to go to the FTB website.

Or, just have your client pay it AT the FTB website.

Thanks for your response.  There appears to be confusion about the due date for the payment - the instructions for the form says March, 15, 2022; a recent "Spidell California Minute" said December 31, 2021...any ideas?

Depends on when you/your client wants the deduction.   This issue was covered in the Spidell webinar.