Firebase Auth Not Working with gatsby on Netlify

I Develop a Gatsby Blog where i use firebase authentication and its work perfect locally on my pc but when i deploy it on netlify it show me an error .
Please Help me it’s working locally but not on netlify !!

10:16:39 PM: failed Building static HTML for pages - 6.848s
10:16:39 PM: error Building static HTML failed for path “/developer/Zia Khan”
10:16:39 PM:
10:16:39 PM: 29 | const [UserActivity, SetuserActivity] = useState();
10:16:39 PM: 30 |
10:16:39 PM: > 31 | firebase.auth().onAuthStateChanged(function (user) {
10:16:39 PM: | ^
10:16:39 PM: 32 | if (user) {
10:16:39 PM: 33 | // User is signed in.
10:16:39 PM: 34 | SetuserActivity(true);
10:16:39 PM:
10:16:39 PM: WebpackError: TypeError: gatsby_plugin_firebase__WEBPACK_IMPORTED_MODULE_5__.d efault.auth is not a function
10:16:39 PM:
10:16:39 PM: - developer.js:31
10:16:39 PM: src/templates/developer.js:31:14
10:16:39 PM:
10:16:39 PM: - arrayLikeToArray.js:1
10:16:39 PM: node_modules/@babel/runtime/helpers/esm/arrayLikeToArray.js:1:1
10:16:39 PM:
10:16:39 PM:
10:16:39 PM: ​
10:16:39 PM: ────────────────────────────────────────────────────────────────
10:16:39 PM: “build.command” failed
10:16:39 PM: ────────────────────────────────────────────────────────────────
10:16:39 PM: ​
10:16:39 PM: Error message
10:16:39 PM: Command failed with exit code 1: gatsby build
10:16:39 PM: ​
10:16:39 PM: Error location
10:16:39 PM: In build.command from netlify.toml:
10:16:39 PM: gatsby build
10:16:39 PM: ​
10:16:39 PM: Resolved config
10:16:39 PM: build:
10:16:39 PM: command: gatsby build
10:16:39 PM: commandOrigin: config
10:16:39 PM: environment:
10:16:39 PM: - DC_SPACEID
10:16:39 PM: - DC_TOKEN
10:16:39 PM: publish: /opt/build/repo/public
10:16:39 PM: Caching artifacts
10:16:39 PM: Started saving node modules
10:16:39 PM: Finished saving node modules
10:16:39 PM: Started saving build plugins
10:16:39 PM: Finished saving build plugins
10:16:39 PM: Started saving pip cache
10:16:39 PM: Finished saving pip cache
10:16:39 PM: Started saving emacs cask dependencies
10:16:39 PM: Finished saving emacs cask dependencies
10:16:39 PM: Started saving maven dependencies
10:16:39 PM: Finished saving maven dependencies
10:16:39 PM: Started saving boot dependencies
10:16:39 PM: Finished saving boot dependencies
10:16:39 PM: Started saving go dependencies
10:16:39 PM: Finished saving go dependencies
10:16:39 PM: Build failed due to a user error: Build script returned non-zero exit code: 2
10:16:39 PM: Failed during stage ‘building site’: Build script returned non-zero exit code: 2
10:16:39 PM: Failing build: Failed to build site
10:16:39 PM: Finished processing build request in 1m33.073795957s

hi there, sorry to be slow to get back to you. are you still experiencing this issue, or were you able to make some progress?