To use the Text To Speech function, you must have created your transcript, and it should be adjusted and fixed. As better your source (punctuation...) as better the outcome!

So once you are done, switch to the recording tab:

On the left side you will then see all the segments and have an indicator as well if they are already recorded or not.

Once you are done with all the preparation of the video, you can start the magic Text-To-Speech.

Therefor, you click the symbol in the area of "Artificial Intelligence":

In the next step, you connect the AI voices to the voices of your characters in your video:

Depending on the duration of your video, it might take a short moment till it is done. Once it is ready, you can adjust the waves inside the segments and export the audio like you recorded yourself.