Hello Chloe,
Welcome to the Prismic community.
This is not possible to reuse slice content at the moment in the Prismic. If I imagine your use-case, you have the same content on multiple pages. To achieve this, you can create another custom-type, add fields and fill in the content. Then you can build relationships between content types with the help of the Content-relationship field. For this, you need to change your code too.
Let me know If I understood your use-case, If not, please elaborate on your use-case, so that I can give some concrete examples after analyzing.
Looking forward to hearing from you back.
Thanks,
Priyanka