let's try indexdb

scripts/popup.js

@@ -0,0 +1,13 @@
+document.getElementById('uploadButton').addEventListener('click', async () => {
+    const miljeInput = document.getElementById('fileInput');
+    const milje = miljeInput.files[0];
+
+    if(!milje) {
+        alert("Please select a milje.");
+        return;
+    }
+
+    const base64Milje = await convertImageToBase64(milje);
+    await saveImage(base64Milje);
+    await displayImage(base64Milje);
+})