Why can't I login to the Google Voice App.

I have to use Google Voice and I am issues logging into the app in my iPhone. Every time I try to "sign in", I keep getting a message that it "Couldn't sign you in" and says that the browser I'm using doesn't support JavaScript, even though I'm pretty sure it does. I tried switching to a different browser and I get the same message. When I try to open it in a new browser, I then get the message, "400. That's an error message. Server can't process the request." I don't really understand what's the issue.

I tried turning off my VPN, updated Google Voice, made sure my phone's software is updated, re-installed the app, and turned the phone on and off, and it's just giving me the same messages. The app is just giving me this problem. No issue when I login with a browser on my laptop. If anyone can kindly provide assistance, that would be greatly apperciated.