how do i see or listen to my voicemail online

I take it that no responses to my question means that any t-mobile person who reads a question here does nothing....

And just as an update, now when I go online to retrieve voicemail, I get a "digits signup"....  How nice, now something else that doesn't work.   Every time I try to register in the browser, I get "There was an error contacting the server. Intenta nuevamente más tarde".    Not sure how many times I'm supposed to try because I've tried from 3 different machines and they all have given the same error over the last 3 days.   So to be disappointed even more, I download the app and it gives me a big white screen marked "Beta"  but only menu items.   Can record my voice and here it play back but wonder how that blank window is going to do anything for me...