Hi, We want to allow our users being able to set their favourite order in order's tag. Because of this, we need to update the order's tag by using Shopify Admin API. It is clearly we can't do it from the Frontend(Shopify online store) because the security issue.
I am thinking to create a backend to call Shopify Admin API, but it needs quite a bit work to develop, deploy and hosting the backend app. Also, the backend app needs to authenticate the Frontend to see if it is a valid Shopify user.
Alternatively, not sure if I can create a Shopify custom app (it seems it is used for creating apps of Shopify Store Admin) and integrate it into online store? Because there is already some template/example code of custom app for authentication, I don't need to worry about the risk of exposing the Admin API's access token at Frontend.