I can edit the LIQUID code in the Shopify theme to add instagram feed. To add instagram feed we will have to write a custom javascript function to make API calls to instagram with the details of which profile, tag name, number of posts, API key, etc, then instagram server send the images url as result, these urls will have to dynamically added with html and CSS to beautify.
I have more than 8 years of experience in web development and designing, you shall expect a professional service and good communication from me.