You're going the wrong direction in this troubleshooting.

I am attempting to access my text messages on the web, from a web browser.  Doesn't matter right now what kind of device.  But to be complete, I am using Firefox or Chrome browser on a Linux computer.  This worked fine last week and for many years prior.  It does not work today because someone made a change on the web site.  I initially connect using the URL https://vtext.com, which redirects to the link you referred me to in the troubleshooting step.   I gave you the result.  Someone turned off this service on the web.  I need it back.  If I could do this on my phone, I would, but I can't for the reasons I've already given.