chore: resolve comments

Author: HuiSF

src/pages/[platform]/build-a-backend/server-side-rendering/index.mdx

@@ -230,13 +230,13 @@ To authenticate users on the server side, you must enable either Amazon Cognito
 
 #### Step 1 - Specify the origin of your app in environment variables
 
-Add the following environment variables to your Next.js app. For example in a `.env` file:
+Add the following environment variable to your Next.js app. For example in a `.env` file:
 
 ```shell title=".env" showLineNumbers={false}
 AMPLIFY_APP_ORIGIN=https://myapp.com
 ```
 
-Ensure this environment variables is accessible in your Next.js app's server runtime.
+Ensure this environment variable is accessible in your Next.js app's server runtime.
 
 <Callout info>
 

src/pages/gen1/[platform]/build-a-backend/server-side-rendering/nextjs/index.mdx

@@ -232,13 +232,13 @@ To authenticate users on the server side, you must enable either Amazon Cognito
 
 #### Step 1 - Specify the origin of your app in environment variables
 
-Add the following environment variables to your Next.js app. For example in a `.env` file:
+Add the following environment variable to your Next.js app. For example in a `.env` file:
 
 ```shell title=".env" showLineNumbers={false}
 AMPLIFY_APP_ORIGIN=https://myapp.com
 ```
 
-Ensure this environment variables is accessible in your Next.js app's server runtime.
+Ensure this environment variable is accessible in your Next.js app's server runtime.
 
 <Callout info>