Use recording software of your choice to make recordings of sentences
spoken by your characters. eg. If your script is:
Cowboy say "This is my horse."
In this case "This is my horse." should be a separate recording.
Upload each such created audio file and give it a unique name
eg. cowboySpeech1
Use them in the animation by using 'using audio cowboySpeech1'. So in this
example the script would be:
Cowboy say "This is my horse" using audio cowboySpeech.