You can download software updates on your iPhone using mobile data, though the method depends on your device model and carrier. While Apple traditionally required a Wi-Fi connection for large updates, modern iPhones—particularly those with 5G—have native settings to permit cellular downloads. 1. Update Using 5G (iPhone 12 and Newer)
If you have an iPhone 12 or a newer model with a 5G data plan, you can enable a specific mode that allows high-bandwidth tasks like iOS updates. Cannot Download iOS Updates Using Cellular Data - AppleVis how to download software update on iphone using mobile data