Due to the way that Telegram interprets the request URL, http_build_query that...

Due to the way that Telegram interprets the request URL, http_build_query that Guzzle uses doesn't work properly. Instead, we now convert all arrays to JSON encoded strings, which get interpreted correctly!

src/Request.php

@@ -180,10 +180,14 @@ class Request
         $has_resource = false;
         $multipart = [];
 
+        // Convert any nested arrays into JSON strings.
+        array_walk($data, function (&$item) {
+            is_array($item) && $item = json_encode($item);
+        });
+
         //Reformat data array in multipart way if it contains a resource
         foreach ($data as $key => $item) {
             $has_resource |= is_resource($item);
-            is_array($item) && $item = json_encode($item);
             $multipart[] = ['name' => $key, 'contents' => $item];
         }
         if ($has_resource) {