Connecting include PUG files

Question

I can't connect another file via "include ./pages/#{page}. pug". Can you tell me how to make it connect?

let renderPage = (res, page) => {
    res.render ('html', {data: {page: 'index'}})
}

html
    head
        title=title
        style
        include ./css/styles.css
    body
        case data.page 
            when 'index'
                include ./pages/#{page}.pug

            default
                p Ошибка 404. Страница не найдена