How do I input text in Figma?

If you're looking to add text in your figma wireframes, all you have to do is use the text tool. Just click on it and then click on the wireframe you want to type your text in. 

How do I input text in Figma?

On the other hand if you're looking to create a text input box that's animated within the prototype, here's a more advanced video that shows you how to do it:

Basically you have to create a component and duplicate multiple input box states which you will have to animate and link based on mouse clicks or buttons pressed.

Unfortunately you won't be able to actually type your text but you will be able to create an animation that imitates typing and looks really convincing on the actual prototype window.

Conclusion

To summarize, if you're looking to add text in your Figma file just use the text tool and click anywhere on your wireframe to place it. To create an interactive input box - it's a bit more complicated but you can follow the video tutorial above.