index.html

<!DOCTYPE html>
<html>
    <head>
        <meta name="viewport" content="width=device-width, initial-scale=1.0">
        <meta charset="UTF-8">
        <meta name="description" content="Simple Web Share example.">
        <meta name="keywords" content="webshare, api, javascript">
    </head>
    <body>
        <button onclick="webshare('440px-TimelessStoriesSVV1.jpg')">Share</button>
        <script>
            const URL = 'https://upload.wikimedia.org/wikipedia/commons/thumb/f/fb/TimelessStoriesSVV1.jpg/440px-TimelessStoriesSVV1.jpg';
            const TYPE = 'image/jpeg';
            const EXT = '.jpg';
            const TITLE = "yourTitle";
            const IS_SAFARI = /^((?!chrome|android).)*safari/i.test(navigator.userAgent);

            function webshare(text) {

                let navigator;
                navigator = window.navigator;
                let data = IS_SAFARI ? { files: [] } : { files: [], text: text, url: URL, title: TITLE };

                var xhr = new XMLHttpRequest();
                xhr.open('GET', URL, true);
                xhr.responseType = 'arraybuffer';
                xhr.onload = function() {
                    if (xhr.status === 200) {
                        var response = xhr.response;
                        //console.log(response);

                        var blob = new File([response], text + EXT, { type: TYPE });
                        data.files.push(blob);
                        //console.log(data);

                        if (navigator.canShare && navigator.canShare(data)) {
                            navigator.share(data)
                            .then(function() {
                                if (IS_SAFARI && (text !== undefined || URL !== undefined || TITLE !== undefined)) {
					                let dataText = { files: [], text: text, url: URL, title: TITLE };
					                navigator.share(dataText);
				                }                                
                            })
                            .catch(function(err) {
                                console.error('Unsuccessful share ' + err);
                            });
                        }
                    } else {
                        console.error('Failed to load ' + URL + ': ' + xhr.status);
                    }
                };
                xhr.send();
            }
        </script>
    </body>
</html>