I created RichTextLabel node, typed some text and it works, okay.
Next I tried to add animated typing ("letter by letter"). I was searching for wait()-like function and I found 2 ways to do this:
1) Use "delta" of function "_process" like in this picture:
2) Use the Timer node.
1st option isn't satisfied cuz just look at my code:
I can't use "delta" provided that I must stay in while-loop. So I should use then the Timer. But I can't understand how it works. I watched some guides, I've done same code as in sources, and I've got no result. The text is just appearing fully and nothing else.
Here's my tries:




Even if I make AddPercentVisible with no arguments, it doesn't work:

If you know how the Timer works, I'll be so thankful for explainings.