I have googled for several hours but I didn't find any article and documentation related to instagram shared button on the web. Does it have or not? Please help!!!
You cannot share media on Instagram using the API. See the docs:
At this time, uploading via the API is not possible. We made a conscious choice not to add this for the following reasons:
- Instagram is about your life on the go – we hope to encourage photos from within the app.
- We want to fight spam & low quality photos. Once we allow uploading from other sources, it's harder to control what comes into the Instagram ecosystem. All this being said, we're working on ways to ensure users have a consistent and high-quality experience on our platform.
来源：https://stackoverflow.com/questions/30542054/does-instagram-have-share-button-or-not