With iOS 13, iPadOS 13, watchOS 6, and tvOS 13, an app must ask permission to use Bluetooth functions except to play audio to a Bluetooth device, which doesn’t require permission. The permission prompt includes a brief explanation of how the app uses Bluetooth, which may include discovering nearby devices, refining location information and other uses.
Permission isn't required for many audio uses like using headphones or speakers, but in some cases, an app that would like to use Bluetooth for certain audio functions might also prompt you for permission.
If you see a prompt asking about an app that would like to use Bluetooth, you can tap OK to allow Bluetooth access. If you don’t want the app to use Bluetooth, tap Don’t Allow.
If you later decide that you want to allow or revoke an app's access to Bluetooth, you can update your choice in Settings > Privacy > Bluetooth.