User Profile

I'm currently befuddled by the entire signing and certificate process. I don't understand what I need, what the team admin needs to do, or how to go about doing it so that I can build the project. We've managed to have this working in the past but I guess the system has changed somewhat. Here's what we have going: A Unity project which hasn't changed from a few years ago. I build the project in unity, open the Xcode project and this: There's an issue with the Signing and Capabilities. If I choose automatic setup it shows an error saying that it requires a development team. I had the account admin add my Apple ID to the team so I'm not sure why that's an issue still. Do I need to pay the 99$ to be able to building Xcode? If I try to do it manually I select the provisioning profile that the account admin sent me and it auto selects the team associated with the provisioning profile I guess but then there's no singing certificate. The error says: There is no signing certificate "iOS Development" found. No "iOS Development" signing certificate matching team ID "V7D5YBZRMV" with a private key was found. So, if someone could explain to me like I'm 5 the entire signing and certificate process is and let me know what we're doing wrong with the team/provisioning profile/certificate setup I would be very much appreciative.