add base path to api too

src/routes/+page.js

@@ -1,5 +1,7 @@
+import { base } from '$app/paths';
+
 export async function load({ url, fetch }) {
-    const corsi = await fetch(`/api/corsi`);
+    const corsi = await fetch(`${base}/api/corsi`);
     return {
         corsi: await corsi.json()
     };

src/routes/corsi/[slug]/+page.js

@@ -1,6 +1,8 @@
+import { base } from '$app/paths';
+
 export async function load({ params, fetch }) {
     const { slug } = params;
-    const response = await fetch(`/api/corsi/${slug}`);
+    const response = await fetch(`${base}/api/corsi/${slug}`);
     const corso = await response.json();
 
     return { corso };

src/routes/gruppi/[slug]/+page.js

@@ -1,6 +1,8 @@
+import { base } from '$app/paths';
+
 export async function load({ params, fetch }) {
     const { slug } = params;
-    const response = await fetch(`/api/gruppi/${slug}`);
+    const response = await fetch(`${base}/api/gruppi/${slug}`);
     const gruppo = await response.json();
 
     return { gruppo };