I actually just had this done literally yesterday lol by a local company. They figured out all the paperwork for me, but I still have to file it through the Philadelphia Tax Center website (or I can mail it). I'm not sure if I can just upload the paperwork or if I have to fill it out line by line but I have to do it (not the tax preparer).

As others noted, you'll want to double check first that your employer wasn't taking the wage tax out. If they did, you don't need to do anything. If they didn't, then yes you need to file.