Multi-modal interface with manipulation of store front end

[WouterNL]

I want to create something similar to shop.app on my shopify store front end. It will be a conversational UI alongside the catalog (visual) UI. both these UIs are seamlessly connected, so if a user writes 'I need new Nikes' the catalog will update to show all Nikes. If a user then clicks a product, the catalog will update to show that product detail page AND the conversational agent will say 'Great choice, Etta from NY also just bought these Nikes!'

I've added a mockup pic below.

I have been doing a lot of research but so far I'm unable to find out how exactly my conversational UI can manipulate the catalog UI. Note that this needs to happen in a unique way for each user, dynamically, based on the conversation.

I would much appreciate any guidance and tips on what architecture to use to achieve this, and what APIs I need to look at to make this dynamic manipulation of front end elements work.

Thanks a lot in advance!