Turborepo + Hono - Relative imports require explicit extensions with node16/nodenext

Trying the template of Turborepo + Hono with the simple setup as it is I can deploy normally.
But if I extend the example to a more real world scenario, for example, introducing more folders and other packages from the monorepo like:

// hono - src/index.ts
import { ... } from "@acme/..."; // from a package in the monorepo
import { auth } from "./lib/auth"; // from a relative file for organization purposes

When trying the build I'm getting this kind of errors.

Error: ../../packages/api/src/index.ts(2,35): error TS2835: Relative import paths need explicit file extensions in ECMAScript imports when '--moduleResolution' is 'node16' or 'nodenext'. Did you mean './orpc.js'?
../../packages/api/src/index.ts(3,32): error TS2835: Relative import paths need explicit file extensions in ECMAScript imports when '--moduleResolution' is 'node16' or 'nodenext'. Did you mean './root.js'?
../../packages/api/src/index.ts(4,27): error TS2835: Relative import paths need explicit file extensions in ECMAScript imports when '--moduleResolution' is 'node16' or 'nodenext'. Did you mean './root.js'?

How can I configure the tsconfig.json or something to make it work?

Start with the Turborepo + Hono template, its tsconfig.json files, and the imports in src/index.ts and packages/api/src/index.ts. Reproduce the node16/nodenext build error and determine the configuration or import convention needed; done means the documented example builds with the shown relative imports.