I can see in the docs here that it's recommended to host videos on a dedicated platform like this and use the integration field to pull the date. Wistia is also specifically mentioned in this comment.
Prismic's Integration Fields allow you to integrate third-party data — such as from e-commerce catalogs or custom APIs — into your repository. And your Custom API format must be compatible with Integration Fields. To learn more about Custom API Format.
Wistia is a Video hosting platform where you can host your video you can then embed them in your document using the Embed field.
@Priyanka I'm afraid that doesn't answer my question. My question was not what is an integration field (or Wistia), but how can I get it to work? Since when I tried, I got an Unauthorized error in Prismic, even though I provided the API key from Wistia (and I can successfully make the request in another application).
Prismic doesn’t support wistia integration directly. You need to use some connector or middleware to convert the data in Prismic’s Integration field compatible format.