Home energy credit for air conditioners - Turbo Tax max at $600, should be $1200?

Per the IRS publication below, the max credit should be $1200.  However, when I enter in Turbo Tax, it maxes out the credit at $600.   I installed 2 x air conditioners and should be eligible for $600 each, up to $1200.  I don't see any way to enter the number of units installed, only the total cost.

 

Home energy tax credits | Internal Revenue Service (irs.gov)