maybe this one works

astro.config.mjs

@@ -0,0 +1,43 @@
+// @ts-check
+
+import mdx from '@astrojs/mdx';
+import sitemap from '@astrojs/sitemap';
+import { defineConfig } from 'astro/config';
+
+
+import rehypeKatex from 'rehype-katex';
+import remarkMath from 'remark-math'
+
+import remarkToc from 'remark-toc';
+
+import cloudflare from '@astrojs/cloudflare';
+
+// https://astro.build/config
+export default defineConfig({
+  site: 'https://example.com',
+  output: "server",
+  markdown : {
+    shikiConfig: {
+      themes : {
+        light : 'gruvbox-dark-medium',
+        dark : 'gruvbox-light-hard'
+      },
+    },
+    remarkPlugins: [
+      remarkMath,
+      [remarkToc, { heading: 'toc', maxDepth: 3 } ],
+    ],
+    rehypePlugins : [
+      rehypeKatex,
+    ]
+  },
+  integrations: [
+    mdx(), 
+    sitemap()
+  ],
+  adapter: cloudflare({
+    platformProxy: {
+			enabled: true,
+		},
+  }),
+});