I used to have a developer manage my app but can no longer get in touch with them and I am required to upload a new build. My question is, do I need the existing build to do so or can I do this myself in from scratch in Xcode? Thanks, Jamie.

Hi all, I had a developer build my APP many years ago and I've not really done a lot with it. I need to upload a new build after making some updates to it but I cannot get in touch with the developer to get the build. It's currently not available for sale as I cannot get past this part of the process. Is there anyway I can get this without them? I'm not overly technical but can figure things out if anyone has any guidance/instructions? Thanks, Jamie.