Update authentication.mdx

Author: Yorkemartin

apps/docs/pages/sdk/guides/authentication.mdx

@@ -19,6 +19,10 @@ Follow the [Onboard & Discover Accounts](/sdk/guides/discover-accounts) guide to
 
 ### Setup API & add `/siwe/nonce`
 
+:::note
+When developing locally in Chrome, you may encounter CORS errors when attempting to return a nonce. This can be resolved by navigating to chrome://flags/ and disabling `Local Network Access Checks`
+:::
+
 Next, we will set up our API endpoints for our authentication flow.
 
 Sign in with Ethereum [requires a nonce](https://eips.ethereum.org/EIPS/eip-4361#message-fields) to be generated by the server to prevent replay attacks. You will need to set up a API endpoint to return a nonce. For example, using [Hono](https://hono.dev) and [Viem](https://viem.sh).