Rest API show No route found for GET error

Question

I'm using Drupal 9.5 to build my api inside my custom module. When I test the API URL on the browser it show me a message

message: "No route found for "GET /api/v1/api_resource""

<?php

namespace Drupal\demo_api\Plugin\rest\resource;

use Drupal\rest\Plugin\ResourceBase;
use Drupal\rest\ResourceResponse;

/**
 * Provides the API resource for the mobile App
 *
 * @RestResource(
 *   id = "demo_api_resource",
 *   label = @Translation("Demo API Resouce"),
 *   uri_paths = {
 *      "canonical" = "/api/v1/api_resource/"
 *   }
 * )
 */
class ApiResource extends ResourceBase {

  public function get() {
    $response = ['message' => 'Hello, this is a rest service'];
    return new ResourceResponse($response);
  }

I did configure in REST UI to accept the GET request with cookie authentication.

What could be the issue here?

Answer 1

I just found out, the issue is caused by the forward slash at the end of the path.

I have to change "canonical" = "/api/v1/api_resource/" to this one "canonical" = "/api/v1/api_resource"

Once I removed the forward slash from the path, the API is response as expected when you request mydomain.com/api/v1/api_resource?_format=json