How to refer to each letter from a StringTable

I have a text in a StringTable in UnrealEngine. I am displaying this text in a dialog widget, using name of StringTable and text key. But I want the text to be typed letter by letter and a sound played after each letter. Tell me how this can be done in blueprints?

It’s not clear how to refer to each letter from the StringTable.

Using the substring node for sure…