Next.js: How to debug with customized koa backend?

[jchbh-duplicate]

I don't found anything about debug backend with dev mode.

Now I can only run npm run build, and npm run start to debug the app.
It is very slowly and inefficiency.

Is there any way to run npm run dev with customized backend enabled?
I test and find npm run dev not start customized backend as expect.

[pukapukan]

https://nodejs.org/en/docs/inspector/

Run your app with --inspect flag and use chrome://inspect to connect Chrome to your app to debug backend logic

[benatkin]

In the custom-koa-server example, package.json is modified to start it by calling node server.js. You should be able to add --inspect to that.