Connecting react to firestore

I'm planning to develop a website with Firestore as database, but not sure which architecture to use.

1. Using the web-client sdk and communicate directly with Firestore from react?

2. Setting up a express server with the admin sdk and call the express server from the react app, check if authenticated, and communicate with Firestore?

Is there any advantages using one or the other?

Have I understood it correctly, or is it only the web-client sdk I should use, and the admin sdk only if I want to develop a dashboard to control usage off the app?