Try integrating once more

common/envs/constants.ts

@@ -2,7 +2,7 @@ import { DEV_CONFIG } from './dev'
 import { EnvConfig, PROD_CONFIG } from './prod'
 import { THEOREMONE_CONFIG } from './theoremone'
 
-export const ENV = process.env.NEXT_PUBLIC_FIREBASE_ENV ?? 'PROD'
+export const ENV = process.env.NEXT_PUBLIC_FIREBASE_ENV ?? 'DEV'
 
 const CONFIGS = {
   PROD: PROD_CONFIG,

web/components/page.tsx

@@ -12,14 +12,11 @@ export function Page(props: {
   children?: any
 }) {
   const { margin, assertUser, children, rightSidebar, suspend } = props
-  useEffect(() => {
+
   if (typeof document !== 'undefined') {
-      // This seems to work...
-      console.log(document)
-      // But not this...
-      initPreviews()
+    // Seems to be undefined; because of https://i.imgur.com/4bMQ8rA.png ?
+    console.log(initPreviews)
   }
-  }, [])
 
   return (
     <>