diff --git a/src/configTypes.ts b/src/configTypes.ts
index f36a3307..a14a0130 100644
--- a/src/configTypes.ts
+++ b/src/configTypes.ts
@@ -90,6 +90,7 @@ export interface ConfigInput {
     // "G-MEASUREMENT_ID"
     measurementId?: string
   }
+  firebaseClientAppName?: string
   tenantId?: string
   cookies: Omit<Cookies.Option & Cookies.SetOption, 'sameSite'> & {
     // The base name for the auth cookies.
diff --git a/src/createUser.ts b/src/createUser.ts
index 4e57d700..16eaf240 100644
--- a/src/createUser.ts
+++ b/src/createUser.ts
@@ -3,6 +3,7 @@ import { User as FirebaseUser } from 'firebase/auth'
 import { DecodedIdToken } from 'firebase-admin/auth'
 import isClientSide from 'src/isClientSide'
 import { Claims, filterStandardClaims } from 'src/claims'
+import { getConfig } from './config'
 
 interface UserDeserialized {
   id?: string
@@ -119,8 +120,9 @@ const createUser = ({
       const { getApp } = require('firebase/app')
       // eslint-disable-next-line global-require,  @typescript-eslint/no-var-requires
       const { getAuth, signOut } = require('firebase/auth')
+      const { firebaseClientAppName } = getConfig()
 
-      signOutFunc = async () => signOut(getAuth(getApp()))
+      signOutFunc = async () => signOut(getAuth(getApp(firebaseClientAppName)))
     }
 
     /**
diff --git a/src/initFirebaseClientSDK.ts b/src/initFirebaseClientSDK.ts
index 22dc7372..96c09215 100644
--- a/src/initFirebaseClientSDK.ts
+++ b/src/initFirebaseClientSDK.ts
@@ -4,8 +4,12 @@ import { getConfig } from 'src/config'
 import logDebug from 'src/logDebug'
 
 export default function initFirebaseClientSDK() {
-  const { firebaseClientInitConfig, firebaseAuthEmulatorHost, tenantId } =
-    getConfig()
+  const {
+    firebaseClientInitConfig,
+    firebaseAuthEmulatorHost,
+    tenantId,
+    firebaseClientAppName,
+  } = getConfig()
   if (!getApps().length) {
     if (!firebaseClientInitConfig) {
       throw new Error(
@@ -13,7 +17,7 @@ export default function initFirebaseClientSDK() {
       )
     }
 
-    initializeApp(firebaseClientInitConfig)
+    initializeApp(firebaseClientInitConfig, firebaseClientAppName)
     if (tenantId) {
       getAuth().tenantId = tenantId
     }
@@ -25,6 +29,9 @@ export default function initFirebaseClientSDK() {
   }
   // If the user has provided the firebaseAuthEmulatorHost address, set the emulator
   if (firebaseAuthEmulatorHost) {
-    connectAuthEmulator(getAuth(getApp()), `http://${firebaseAuthEmulatorHost}`)
+    connectAuthEmulator(
+      getAuth(getApp(firebaseClientAppName)),
+      `http://${firebaseAuthEmulatorHost}`
+    )
   }
 }
diff --git a/src/useFirebaseUser.ts b/src/useFirebaseUser.ts
index e5bc20f5..f655633f 100644
--- a/src/useFirebaseUser.ts
+++ b/src/useFirebaseUser.ts
@@ -175,10 +175,19 @@ const useFirebaseUser = () => {
     }
 
     // https://firebase.google.com/docs/reference/js/firebase.auth.Auth#onidtokenchanged
-    const unsubscribe = onIdTokenChanged(getAuth(getApp()), onIdTokenChange)
-    return () => {
-      unsubscribe()
-      isCancelled = true
+    try {
+      const { firebaseClientAppName } = getConfig()
+      logDebug(`[withUser] firebaseClientAppName |${firebaseClientAppName}|`)
+      const app = getApp(firebaseClientAppName)
+      logDebug('[withUser] App loaded', app)
+      const unsubscribe = onIdTokenChanged(getAuth(app), onIdTokenChange)
+      return () => {
+        unsubscribe()
+        isCancelled = true
+      }
+    } catch (error) {
+      logDebug('[withUser] init error', error)
+      throw error
     }
   }, [])