Why is there no Instagram Share Button?

My client wants to add an Instagram "SHARE BUTTON" below each of the products on their product pages, but Instagram is oddly not listed as an option in the SHARE BUTTONS feature. Is there a way around this?

Client is using the MARTA template

Thanks in advance for any suggestions and/or solutions!

Chris

Sharing to Instagram has never really been an option anywhere (not just within Squarespace) due to the nature of Instagram itself. The only method Instagram gives its users to post is via their mobile app. Instagram doesn't work like Pinterest, where you can see another user's content and then pin that content to your own wall. It's all supposed to be your own content.

Instagram is a social network especially designed for mobile usage.So, it is much more obvious that it does not work out for desktops applications for sharing of posts or blogs.