Sample code does not allow form submission

[faanskit]

Tried to follow the instruction, with partial success.
Site comes up, but submission fails.

How to reproduce

(1) Create a new Netlify server from template using url
(2) Clone to developer PC (git clone....)
(3) Install dependencies with npm install
(4) Run locally using netlify dev

Result: A server running on port 8888
http://localhost:8888/

Logs

◈ Netlify Dev ◈
◈ Ignored general context env var: LANG (defined in process)
◈ Setting up local development server
Cleaned up .netlify\functions-internal.
◈ Starting Netlify Dev with Nuxt

> [email protected] dev
> nuxt

ℹ Listening on: http://localhost:3000/
ℹ Preparing project for development
ℹ Initial build may take a while
✔ Waiting for framework port 3000. This can be configured using the 'targetPort' property in the netlify.toml
i Discovered Components: .nuxt/components/readme.md
✔ Builder initialized
✔ Nuxt files generated

   ┌─────────────────────────────────────────────────┐
   │                                                 │
   │   ◈ Server now ready on http://localhost:8888   │
   │                                                 │
   └─────────────────────────────────────────────────┘

◈ Loaded function joke
[webpackbar] ℹ Compiling Server
[webpackbar] ℹ Compiling Client
[webpackbar] ✔ Server: Compiled successfully in 3.55s
[webpackbar] ✔ Client: Compiled successfully in 3.92s
ℹ Waiting for file changes
ℹ Memory usage: 189 MB (RSS: 276 MB)
ℹ Listening on: http://localhost:3000/
◈ Rewrote URL to /.netlify/functions/joke
Request from ::1: GET /.netlify/functions/joke
Response with status 200 in 178 ms.

(5) Populating the form with sample data (test, [email protected], test) and pressing Submit.
Result:
http://localhost:8888/success
Function not found...

Logs:

 »   Warning: Missing form submission function handler
Request from ::1: POST /success
Response with status 404 in 1 ms.
 »   Warning: Missing form submission function handler
Request from ::1: POST /success.html
Response with status 404 in 1 ms.
 »   Warning: Missing form submission function handler
Request from ::1: POST /success.htm
Response with status 404 in 1 ms.
 »   Warning: Missing form submission function handler
Request from ::1: POST /success/index.html
Response with status 404 in 1 ms.
 »   Warning: Missing form submission function handler
Request from ::1: POST /success/index.htm
Response with status 404 in 0 ms.

Same result on production site. 404 error for /success page.

ps. Log message is confusing with both port 3000 and 8888 indicated,