how to Get same cart data of customer on mobile app and website with api

[IffiChaudhry14]

Hello I have a store on Shopify and i,m building it,s app using Storefront API,s. And  i want to Get same cart data of customer on mobile app and website with api but when i use cart api it's geneate cart id and when we add items to it's cart it doesn,t goes to same customer account on shopify website. Plz help me is it possible to add same cart with same customer on app and website.

@Staff 
@vkstaff