ERROR: Please sign or rebuild your APK using a production certificate or verify your keystore build settings are correct. - Oculus APK upload Error

When I upload my APK to the Oculus developer hub it gives this error : ERROR: Please sign or rebuild your APK using a production certificate or verify your Keystore build settings are correct. I couldn't figure out how to troubleshoot the problem. If anybody can help please do so, It would be greatly appreciated. Here is the GitHub Repository if that helps.