Get src parameter value from with scraper

Question

I want to get a url from <img> (inside of src parameter) html tag using scraper. I've tried this code

let image_selector = scraper::Selector::parse("#photoInner > ul > li:nth-child(2) > div > img").unwrap();
let mut inner_image: String = next_document
                    .select(&image_selector)
                    .flat_map(|el| el.attr())
                    .collect();
println!("{:?}", inner_image);

But I'm getting that attr method not found in ElementRef<'_>. I'm not sure how to chain the methods to make this work.

HTML looks like this

<img onerror="this.src='/ui/utility/common/svg/iconI_no-image.svg?s=1&amp;w=350&amp;h=350';" alt="" src="https://image1.homes.jp/smallimg/image.php?file=%2Fdata%2F1700013%2Fsale%2Fimage%2F0010012-1.jpg&amp;width=620">