You can get started with Text Animator for Godot in very few simple steps. To get a better understanding of the tool's fundamentals, here is how to get started to animatae your texts:
As the first step, you need to import Text Animator in your project.
Import the "Text Animator" zip content in your project base folder, you will see two plugins.
Build the project once and activate first EditorUtils and then TextAnimator (in this order).
After enabling both plugins, build again and restart your godot project.
Add a RichTextLabel in your scene.
Add a TextAnimator node as a child.
Your scene tree should look like this:

Done! We told you that it would have been quick! Your text is now ready for effects.
P.S. Please make sure to have the TextAnimator node as a child of the RichTextLabel you want to control.
When importing the asset, you can include and have a look at the "Example Scenes". If you do, please start from the "00-Welcome!"

You can safely remove/delete the Example Scenes folder when you don't need them anymore! (and reimport them again anytime)
Here’s how to quickly animate your first texts.
To add effects in your text, you can use rich text tags like this: “I'm <shake>freezing</shake>”, where "shake" is an ID for a built-in effect.
Try writing a text by experimenting with the following tags: <wiggle> <shake> <wave> <bounce>, like “<wiggle>I'm joking</wiggle> hehe now <shake>I'm scared</shake>”, then enter Unity’s Play mode.
To show letters dynamically (like a typewriter):
Add a Node with the TypewriterByCharacter script, as a child of the same RichTextLabel node.
Bind the TextAnimator node to the Typewriter through the inspector
Your text is animating letters based on the effects you’ve written, and it's also ready to display characters one after another!