Prisma

Hello. Unfortunately I am struggling a bit to get calculated fields resolved when using prisma bindings or prisma clients and fragments (works with info object).

Imagine I want to calculate a hmac from the email of a User type. I add a custom resolver called hmac in the User resolver and add hmac to the User type in the schema.graphql.  Now I can query the hmac from the frontend using the info object and it will be returned without a problem.

If however I am trying to resolve / receive this calculated value from a fragment I will receive an error like "Cannot query field 'hmac' on type 'User'."

Code:
const user: any = await prisma
    .user({
      id: ctx.req.userId,
    })
    .$fragment(`
        fragment UserWithPosts on User {
          id
          email
          hmac
        }
    `);

What am I doing wrong? How to receive custom resolver values using fragments / the prisma client or binding?