I am assuming you are referencing the pass-through entity tax (PTET) in New York.  Per NY guidance the election/tax calculation must be made online thru their Business Portal.  https://www.tax.ny.gov/online/

The software has been updated for PTET credits to report the associated credits on the shareholder's K-1. To enter the PTET credits and taxable income: 

Navigate to the bottom of the CT-34-SH, p1-3 and a smart worksheet has been added.  In this smart worksheet, the user can enter the PTET information and the amounts will be distributed to the K-1s on a prorata basis.  You will see this information in the Supplemental Stmt at the bottom of each shareholder K-1.