Express.raw Guidance Please

I'm new to Express and trying to use it with Firebase Cloud Functions to integrate with Stripe API.

I'm running into a problem with the concept of extracting the raw body of the request; Stripe needs this to verify the signature.

All of the examples suggest this is an easy task using examples provided. No matter what I do, the body is converted to JSON.

I'm not sure if this is a good place to ask such a question, but I'm coming up empty on stack overflow.