feat(universalLogin): use unauth-ed api endpoint to fetch login URL (#5940)

* feat(universalLogin): use unauth-ed api endpoint to fetch login URL

* chore: prettier

Author: ChitlangeSahas

src/onboarding/containers/LoginPage.tsx

@@ -20,13 +20,6 @@ import LoginPageContents from 'src/onboarding/containers/LoginPageContents'
 import {CLOUD} from 'src/shared/constants'
 import {isFlagEnabled} from 'src/shared/utils/featureFlag'
 
-let getQuartzLoginUrl
-
-if (CLOUD) {
-  getQuartzLoginUrl =
-    require('src/client/uiproxydRoutes').getUiproxyQuartzLoginUrl
-}
-
 const EMPTY_HISTORY_STACK_LENGTH = 2
 
 export const LoginPage: FC = () => {
@@ -63,11 +56,21 @@ export const LoginPage: FC = () => {
   } else {
     if (isFlagEnabled('universalLogin')) {
       if (CLOUD) {
-        getQuartzLoginUrl({})
+        fetch('/api/env/quartz-login-url')
           .then(response => {
-            const redirectUrl = response.data
-            console.warn('Redirect to cloud url: ', redirectUrl)
-            window.location.replace(redirectUrl)
+            response
+              .text()
+              .then(response => {
+                const redirectUrl = response
+                console.warn('Redirect to cloud url: ', redirectUrl)
+                window.location.replace(redirectUrl)
+              })
+              .catch(error => {
+                console.error(
+                  'Failed to fetch /api/env/quartz-login-url',
+                  error
+                )
+              })
           })
           .catch(error => console.error(error))
         return