it is possible, but it's better to test your code with pad to avoid any error when you add the padd connection to your code, and also to properly manage the pad during scan...
You have to add IO Pads in your RTL in the same way you add macros (like memories or analog blocks). What you can do create one verilog file consists all IO Pad ports & instance and instaintiate that in your top-level RTL with proper connections.