"Signing key not found" NEED HELP

I am trying to make a ios distribution build with Unreal Engine 4.18.1 but it fails packaging with the error message “signing key not found”. My mobile provisioning profile and my distribution certificate is showing green in project settings. I also ensured that the certificate with it’s attached key pair is in the kechain access under the system and login tab. I really cannot find what I am doing wrong here? I am on macOS Sierra v10.12.6