TS(2742) error when trying to create client

import * as trpcExpress from '@trpc/server/adapters/express'
import { renderTrpcPanel } from 'trpc-panel'
import { createContext } from './context'
import { Handler } from 'express'
import { createRouter } from './createRouter'

export const createApi = (path: string): { trpc: Handler, panel: Handler } => {
  const router = createRouter();

  return {
    trpc: trpcExpress.createExpressMiddleware({
      router,
      createContext
    }),
    panel: (_, res) => res.send(renderTrpcPanel(router, { url: `${path}/trpc`}))
  }
}

export type AppRouter = ReturnType<typeof createRouter>