Can't use Cloudflare D1 database with Hono backend on Cloudflare Workers

import { betterAuth } from "better-auth";
import { anonymous } from "better-auth/plugins";
import { Kysely } from "kysely";
import { D1Dialect } from "kysely-d1";
// Can't get a reference of D1 from here since it's outside the incoming request scope

export const auth = betterAuth({
  database: {
    db: new Kysely({
      dialect: new D1Dialect({
        database: process.env.DB as unknown as D1Database, // this results in database: undefined
      }),
    }),
    type: "sqlite",
  },
  emailAndPassword: {
    enabled: true,
  },
  plugins: [anonymous()],
});