Changing User Agent Not Working for Google

On my desktop PC, I went to Google to create a Google account. After filling in my name, my new email address, etc, it asked for my phone number. But when I create an account on my phone, it doesn’t ask for my phone. So, I figured if I change the user agent to an iPhone on my Windows 10, it will let me create an account without asking for phone.

However, that didn’t work. Why does it think I am on a PC when the user agent is an iPhone?