I tried to hit a specific route:

http://127.0.0.1:3333/store/products?productId=4

but the server give me this error:

"message": "E_ROUTE_NOT_FOUND: Cannot DELETE:/store/products",

"stack": "HttpException: E_ROUTE_NOT_FOUND: Cannot PATCH:/store/products\n   

You are not hitting the right url and your route is wrong.

The right url with your route.js is :

http://127.0.0.1:3333/store/products/4
                                     ^- Product id

and the route :

Route.delete('/products/:productId', 'ProductsController.delete')
//                      ^- use : for url parameter

Routing explanation

Body data & url parameters are totally different.

Please read : What is the difference between URL parameters and query strings?

Body data

Request body (json).

Documentation : https://preview.adonisjs.com/guides/http/form-submissions#reading-form-data

Example url :

http://127.0.0.1:3333/products?name=hello

Route example :

Route.post('/products', 'MyController.myFunction')

Controller :

public async myFunction ({ request }: HttpContextContract) {
  const data = request.only(['name'])
  // ...
}

Url parameter

Specify dynamic url parameter.

Documentation : https://preview.adonisjs.com/guides/http/routing#dynamic-urls

Example url :

http://127.0.0.1:3333/products/1

Route example :

Route.post('/products/:id', 'MyController.myFunction')

Controller :

public async myFunction ({ params }: HttpContextContract) {
  const id = params.id
  // ...
}