To distribute a new iOS app release via Microsoft Visual Studio App Center for devices in a private distribution group, which certificate file type must you upload?

For distributing iOS apps, especially for private distribution groups in App Center, a .p12 file is required. This file contains both the signing certificate and its associated private key, which are essential for signing the app and allowing it to be installed on registered devices. .cer files contain only the public key of a certificate and are used for certificate requests or verifying signatures, not for signing applications. .pfx files are a Windows-specific format for storing certificates and private keys, similar to .p12 but less commonly used for iOS development. .pvk files contain only a private key, without the corresponding certificate, making them insufficient for signing.