You can do online shopping on Instagram by following these steps:

1. Find a shop on Instagram: Discover the shops and brands you’re interested in by using the search feature, exploring the Explore tab, or tapping on the “Shop” tab on the bottom menu bar.
2. Browse products: Once you find a shop you like, browse their products and click on the ones you’re interested in. This will take you to the product page, where you can see more information and photos of the product.
3. Add to cart: If you want to purchase the product, click on the “Add to Cart” button. You can continue browsing the shop and add more products to your cart, or proceed to checkout.
4. Check out: When you’re ready to check out, click on the shopping bag icon on the top right corner of the screen. Review your order and click on the “Checkout” button to enter your shipping and payment information.
5. Complete your purchase: Once you’ve entered your information, click on the “Place Order” button to complete your purchase. You’ll receive an email confirmation with the details of your order.

Note that not all Instagram shops allow you to purchase directly on the app. Some may redirect you to their website or require you to place your order through direct message or email. Always make sure to read the shop’s policies and terms of service before making a purchase.