How can I edit a text block

I did answer your question with a link to an example:

There are two key parts of the example:

A method to dynamically set the text:
SetDynamicText<localizes>(value:string) : message = "{value}"

And setting the message in your text block widget:
_textWidget.SetText(SetDynamicText("Complete!"))

I can only hold your hand so far, at some point you need to learn it on your own.