Is there a way to update my iOS without WiFi?

You can update by connecting your device to a computer and using finder (Mac) or iTunes (Windows).

No, Wi-Fi is a requirement.

But you can also update using computer iTunes or Finder with iPhone connected and selected.

On iPhone 11 and older, you'll need Wi-Fi to download and install updates. On iPhone 12 and newer, you can download and install updates over 5G by turning on "Allow More Data on 5G" in Cellular settings.

You can also update your phone with a Mac or with a PC with iTunes installed.