Where do you find local tax forms?

The forms are available online.

• First, you have to find the municipality and withholding rates for where you live. 
• Enter your street and work address in the form. The tax is generally based on your home address. If you do not have a work address, enter your home address in the work address section.
• Click Find my information
• Write down the PSD Code and the Total taxes to be Withheld
• Scroll down to see the Tax Collectors for your area
• Go to their website and fill out the forms. The local tax form can usually be efiled, but you may need to print and mail it if payment is owed.

You are not going to find PA local forms in TurboTax software.

TurboTax only prepares a few city or local tax returns as an extra step in your state return.  For most local tax returns you are on your own.  Your only record of paying your local tax will be your own bank/credit card records

https://ttlc.intuit.com/questions/1899325-which-city-tax-returns-can-i-do-in-the-turbotax-state-program