Picture tag and onerror fallback image isn't being called

I'm trying to use onerror with source tag but the function isn't being called.

<picture>
                <source srcset="<?=home(1).str_replace(array('.jpg', '.png', '.gif'),".webp",$movie->thumb3) ?>" type="image/webp" onerror="fallback()">
                <source srcset="<?=home().$movie->thumb3 ?>" type="image/jpeg">
                <img src="<?=home().$movie->thumb3 ?>" alt="<?=$movie_title?>">
            </picture>

javascript

function fallback() {
      var src = $(this).attr("srcset");
        src = src.replace("https://webp","https://images");
        $(this).attr("srcset",src);
    }

The fallback image isn't being used? How do i solve?