how can I build a flavor buy box similar to this website

[DANPEE]

is there any app the can help me build a flavor box similar to the one on this website:  https://huel.com/products/huel-hot-savoury

also the customer must add 3 bags to be able to order

[Dirk]

Hey, @DANPEE 

This is known as a product bundling feature. You can use a third-party app to integrate this sort of functionality into your own Shopify store. Below I've compiled a couple of app options that should suit your needs.

• Bundable - $18.50/month. 14-day free trial. - App Demo  - App Developer Support 
• Bundle Builder - $25/month. 30-day free trial. - App Demo - App Developer Support 

If there is anything else I can help you with, please let me know.