Hello Sophia_rberry,
Thank you for posting in the Apple Support Communities. We'd like to share some information with you.
As it turns out, since Siri requests are associated with a random identifier that isn't linked to your Apple ID, email address, or any other personal data, there may not be a way to review that past request. Check out how Siri uses input data at the resources below.
Ask Siri, Dictation & Privacy
How to delete your Siri history
With that said, you're welcome to share your feedback about viewing past Siri requests. Feel free to share that feedback with Apple here:
Product Feedback
In the meantime, you can check to be sure Siri always speaks when activated - even in Silent Mode - before completing a task. To do this from an iPhone, tap on Settings > Siri & Search > Siri Responses > Always. Here's more information about managing Siri settings:
Change Siri settings on iPhone
We hope this information is useful. Kind regards.