TRPC type issue

  create: t.procedure
    .input(createFileSchema)
    .mutation(async ({ input, ctx }) => {
      const userId = ctx.session?.user?.id

      if (!userId) {
        throw new Error('Not authenticated')
      }

      const file = await prisma?.file.create({
        data: { // error
          User: {
            connect: {
              id: userId,
            },
          },
          ...input,
        },
      })

      return file
    }),

      Types of property 'userId' are incompatible.
        Type 'string' is not assignable to type 'undefined'.ts(2322)
index.d.ts(5945, 5): The expected type comes from property 'data' which is declared here on type 

const createFileSchema = z.object({
  id: z.string().nullish(),
  userId: z.string(),
  url: z.string().min(1, 'Url is required.'),
  title: z.string().min(1, 'Title is required.'),
  description: z.string().min(1, 'Description is required.').nullish(),
  createdAt: z.string().nullish(),
  updatedAt: z.string().nullish(),
})