Symfony4: Unable to find the controller for path "/api/login_check". The route is wrongly configured

I am tyring to set up symfony4 api JSON login by JWT.The api platform core bundle is installed and I followed this instruction: https://api-platform.com/docs/core/jwt/

I created the custom user provider as described.By opening the URL /api/login_check the error message "Unable to find the controller for path "/api/login_check". The route is wrongly configured." occurs.

By sending a POST request I get the error page in html.

This is my routes.yaml:

#index:#    path: /#    controller: App\Controller\DefaultController::indexapi_login_check:    path: /api/login_check

And here is my security.yaml:

security:    encoders:        App\Security\User\WebserviceUser: bcrypt    # https://symfony.com/doc/current/security.html#where-do-users-come-from-user-providers    providers:        webservice:          id: App\Security\User\WebserviceUserProvider        in_memory: { memory: ~ }        main:          entity: { class: App\Entity\User, property: email }    firewalls:        login:            pattern:  ^/api/login            stateless: true            anonymous: true            provider: webservice            json_login:                check_path: /api/login_check                username_path: email                password_path: password                success_handler: lexik_jwt_authentication.handler.authentication_success                failure_handler: lexik_jwt_authentication.handler.authentication_failure        api:            pattern: ^/api            provider: webservice            stateless: true            guard:                authenticators:                    - lexik_jwt_authentication.jwt_token_authenticator        dev:            pattern: ^/(_(profiler|wdt)|css|images|js)/            security: false        main:            anonymous: ~            # activate different ways to authenticate            # http_basic: true            # https://symfony.com/doc/current/security.html#a-configuring-how-your-users-will-authenticate            # form_login: true            # https://symfony.com/doc/current/security/form_login_setup.html    # Easy way to control access for large sections of your site    # Note: Only the *first* access control that matches will be used    access_control:        - { path: ^/api/login, roles: IS_AUTHENTICATED_ANONYMOUSLY }        - { path: ^/api,       roles: IS_AUTHENTICATED_FULLY }

bin/console debug:route returns:

 --------------------------- -------- -------- ------ -------------------------------------   Name                        Method   Scheme   Host   Path                                  --------------------------- -------- -------- ------ -------------------------------------   api_entrypoint              ANY      ANY      ANY    /api/{index}.{_format}                 api_doc                     ANY      ANY      ANY    /api/docs.{_format}                    api_jsonld_context          ANY      ANY      ANY    /api/contexts/{shortName}.{_format}    api_users_get_collection    GET      ANY      ANY    /api/users.{_format}                   api_users_post_collection   POST     ANY      ANY    /api/users.{_format}                   api_users_get_item          GET      ANY      ANY    /api/users/{id}.{_format}              api_users_delete_item       DELETE   ANY      ANY    /api/users/{id}.{_format}              api_users_put_item          PUT      ANY      ANY    /api/users/{id}.{_format}              _twig_error_test            ANY      ANY      ANY    /_error/{code}.{_format}               api_login_check             ANY      ANY      ANY    /api/login_check                      --------------------------- -------- -------- ------ -------------------------------------

Does anybody know what my mistake is?