Lost all Files on Active App

I lost all the files to an app thats currently on the App Store. My Firebase is not recognizing the app anymore. So I pulled it off the market before anyone Purchased the app. My plan is to rebuild the app over the next couple of weeks with some updates I was working on for 1.1. How do I proceed? Do I start a new project in Xcode and give it the same name or a different one? How will I get it to be recognized by AppStore connect as the same app? Is it just the bundle iD? Yep first time doing this. I needed an app to do something and there wasn’t one out there that did what I needed so I learned to code a little bit and built what I needed. Hoping to share it with others through the App Store but the learning curve here has been steep. Appreciate any help. This stuff keeps me up at night.

Lost all Files on Active App
 
 
Q