Hey there @LizQuintanilla ,
Thanks for asking on the Instructure Community!
Assuming you're a student, I feel it would be best to reach out to your Instructor directly about this issue. VoiceThread is not a feature provided by Canvas specifically, and would be something that your school or institution purchased and integrated into your school's Canvas instance.
If you however are a teacher (and you can do this as a student too, probably), I recommend reaching out to your school's Canvas admin team. There's a possibility that this app wasn't configured for the course correctly, and it will need fixed on their end.
All the best to you!
Noah