You might need to enter your developer credentials in Xcode. You can start by double clicking your IOS Xcode project in your project folder.
Top Left → XCode → Settings → Accounts and enter your developer information here.
After that’s done, you can click on the folder icon in Xcode → Click and open Games → Click your game name → And click the file that doesn’t say “Editor”. You’ll see a “Signing and Capabilities” tab in the center of the screen. Click that and make sure your information is there. It should auto populate.