You have a few options when it comes to downloading the iOS 11.4.1 update on your phone, tablet, or iPod.
If you plan on installing the iOS 11.4.1 update Over-the-Air (OTA) through your device's Settings, you'll need to have at least a 50% charge.
If you want to avoid installing the update via iTunes, now would be a good time to find a Lightning Cable and charge up your phone or tablet.
If you do decide to install Over-the-Air, and you want to get it downloaded and installed ASAP, you'll want to find a fast Wi-Fi connection.
You can also install the iOS 11.4.1 update through iTunes. Simply plug your device in, click the correct device under the Devices tab and check for an update.