1.14.x is end of life and no longer supported.
That being said depended fields are not a concept or feature in osTicket at this time. The only exception to that is that Help Topic, to add a form.
You can use the Help Topic as the first selection, and add a different form to each one.
example:
-- Help Topics --
Account Payable
Billing
Facilities
Information Technology
If you select Accounts Payable. its presents a form with your Vendors as a list so the person can select a vendor.
If you select Billing, it doesn't display an additional form.
If you select Facilities, it presents a list with your physical locations or maybe room numbers
if you select Information Technology it presents a list of Common issues they can select form (printer, phone, etc)