public static function handle_activate() {
    if ( ! current_user_can( 'manage_woocommerce' ) && ! current_user_can( 'manage_options' ) ) {
        wp_die( esc_html__( 'Keine Berechtigung.', 'wc-dsgvo' ) );
    }

    check_admin_referer( self::NONCE_ACTIVATE );

    $key = isset( $_POST['wc_dsgvo_license_key'] ) ? wp_unslash( $_POST['wc_dsgvo_license_key'] ) : '';
    self::set_license_key( $key );

    self::remote_check( 'activate' );

    $data = self::get_license_data();
    if ( ! empty( $data['status'] ) && 'active' === $data['status'] ) {
        self::update_license_data( array(
            'status'     => 'active',
            'last_check' => time(),
        ) );
        self::redirect_back( 'activated' );
    }

    // Erster kurzer Validate-Fallback
    usleep( 500000 ); // 0.5 Sekunden
    $fallback = self::remote_check( 'validate' );
    $data     = self::get_license_data();

    if ( ! is_wp_error( $fallback ) && ! empty( $data['status'] ) && 'active' === $data['status'] ) {
        self::update_license_data( array(
            'status'     => 'active',
            'last_check' => time(),
        ) );
        self::redirect_back( 'activated' );
    }

    // Zweiter kurzer Validate-Fallback
    usleep( 700000 ); // 0.7 Sekunden
    $fallback = self::remote_check( 'validate' );
    $data     = self::get_license_data();

    if ( ! is_wp_error( $fallback ) && ! empty( $data['status'] ) && 'active' === $data['status'] ) {
        self::update_license_data( array(
            'status'     => 'active',
            'last_check' => time(),
        ) );
        self::redirect_back( 'activated' );
    }

    self::redirect_back( 'error' );
}