Such a pity that you couldn't get the Text Input Extension to work for you

. It's the extension I had the least amount
of trouble with. Are you sure it is enabled?
I'm attaching the piece of code I used it into, in case it helps you give it a second chance.
The When Drawing events just work to draw some rectangles where the text field will be so it actually looks like a place
where the player can type.
As for "not allowing the player to move or press other commands if he's typing"-problem, I suggest using a boolean.
Like, if you use the Text Input Extension, you can check if that text-box exists or is not null, and then turn on another boolean that renders the other commands invalid.
I usually have a GA Disable Movement that handles these situations. The codes where my key-is-pressed are always start with "if not Disable Movement", and it saves me from more trouble.
//Added a printscreen of the result from this code.
"Qual é o seu nome?" translates to "What is your name?" and "Meu nome" translates to "My name" :>