install adapter-static and configure

npm i -D @sveltejs/adapter-static@next

package.json

@@ -13,6 +13,7 @@
   },
   "devDependencies": {
     "@sveltejs/adapter-auto": "next",
+    "@sveltejs/adapter-static": "^1.0.0-next.24",
     "@sveltejs/kit": "next",
     "@types/cookie": "^0.4.1",
     "@typescript-eslint/eslint-plugin": "^4.31.1",
@@ -34,4 +35,4 @@
     "@lukeed/uuid": "^2.0.0",
     "cookie": "^0.4.1"
   }
-}
+}

svelte.config.js

@@ -1,6 +1,9 @@
-import adapter from '@sveltejs/adapter-auto';
+import adapter from '@sveltejs/adapter-static';
 import preprocess from 'svelte-preprocess';
 
+const dev = process.env.NODE_ENV === 'development';
+
+
 /** @type {import('@sveltejs/kit').Config} */
 const config = {
 	// Consult https://github.com/sveltejs/svelte-preprocess
@@ -8,6 +11,9 @@ const config = {
 	preprocess: preprocess(),
 
 	kit: {
+		paths: {
+			base: dev ? '' : '/staticspaceiframe/julien-c/sveltekit-demo/build',
+		},
 		adapter: adapter(),
 
 		// hydrate the <div id="svelte"> element in src/app.html