It’s not easy for me to make it work

I can’t find references about how to block endpoints. You can use a code like this:

// add user id to the token to store on your front end
function add_user_id_and_role_to_jwt_response( $data='', $user='' ) {
    $data[ 'user_id' ] = $user->data->ID;
    return $data;
}
add_filter( 'jwt_auth_token_before_dispatch', 'add_user_id_and_role_to_jwt_response', 10, 2);

// create a callback function
function token_jwt_permission_callback ( WP_REST_Request $request = null ) {

    $user_id = sanitize_text_field( $request->get_param( 'user_id' ) );

    $jwt = new Jwt_Auth();
    $jwt_public = new Jwt_Auth_Public( $jwt->get_plugin_name(), $jwt->get_version() );

    $user_id_at_token = $jwt_public->determine_current_user( $user_id );
    $validate_token = $jwt_public->validate_token( $request );
    $valid_token = false;
    if ( !is_wp_error( $validate_token ) ) {
        $valid_token = ( $validate_token[ 'code' ] === 'jwt_auth_valid_token' );
    }

    if ( !$valid_token || $user_id != $user_id_at_token ) {
        return false;
    }

    return true;

}


// when register your route:
        register_rest_route( self::get_plugin_namespace(), '/get_services', array(
            array(
                'methods'  => WP_REST_Server::CREATABLE,
                'callback' => array( $this, 'get_services' ),
                'permission_callback' => 'token_jwt_permission_callback', // <<<<<< set your callback here
            )
        ) );