Sorry you are facing this issue, it would be my pleasure to help you.
Welcome to the Shopify community!
Thanks for your good question.
sorry Shopify default allow Facebook, Twitter, and Pinterest options other is not possible use maybe free apps
This is an accepted solution.
My name is Lilith, I'm on the Social Care team at Shopify.
I'm glad that you're thinking of your business growth through existing customers. There is no better conversion rate than that of customers sharing your site with their friends.
Aside from the built-in share buttons on a specific theme, you may be using, you can use code to add new buttons. There are a couple of third-party articles that can help.
Alternatively, there is an app that can create those buttons as well. It's called Social Share Buttons and there is a fee attached to using the app. Be sure to check the page before installing to ensure that you're comfortable with a paid app.
As a general tip, you can find the code to generate a share button for any social platform. You can jump into the website's links for marketing kits or assets, usually, you'll find those in the footer menus.
The other option I highly recommend is hiring one of our partners to help you with this. You can find a suitable Shopify Partner in the Experts Marketplace or request a quote by following this guide here.
One thing to remember is to be selective on the platforms you want to add on that product page as sharing buttons. Try to keep it at no more than 3 or so buttons for sharing as that will give the visitor a less overwhelming experience and will make it easier for them to decide on which profile they want to share.
Based on the customer target you intend to sell to, try to keep your social media presence and share to those platforms with target customers as their highest user base. We have a pretty good breakdown of the target customers for common platforms in one of our Community posts to help!
That post also contains some great tips on how to increase engagement on social media to lower the cost of marketing and increase conversion.
Let me know how you do with the information above! I'm happy to answer any questions you think of as you work on your business.