maybe work

index.html

@@ -23,7 +23,7 @@
 						<div class="flex items-center justify-center">
               <input
                 type="file"
-                name="file"
+                name="map"
                 class="bg-gray-700 text-white font-bold py-2 px-4 rounded"
               />
 						<div class="flex items-center justify-center">

upload.php

@@ -29,8 +29,7 @@ function isZipFile($file)
 
 $mapId = generateMapId(); // the id of the map
 
-$map = $_FILES["map"];
-$file = $map["tmp_name"];
+$file = $_FILES["map"]["tmp_name"]; // the file to upload
 
 if (!isZipFile($file)) {
   echo "The file is not a zip file";