diff --git a/dta.zip b/dta.zip
index 02e077fbd7ea59ae611a92947d44c0dc10d6d0b9..01aa7904c3ee85d7f0d91d2f601f81b77e96df83 100644
Binary files a/dta.zip and b/dta.zip differ
diff --git a/dta/classes/backend.php b/dta/classes/backend.php
index c6a0a3a410e2c91b7154dc21e8c2e3b6b463b65e..7ca08f49e180ca0a2bd41bfe06c9bbf2bc15c01f 100644
--- a/dta/classes/backend.php
+++ b/dta/classes/backend.php
@@ -79,17 +79,18 @@ class DtaBackendUtils {
      * Sends submission config or archive to backend to be tested.
      *
      * @param stdClass $assignment assignment for the submission
+     * @param int $submissionid submissionid of the current file
      * @param stdClass $file submission config file or archive with submission
      * @return string json string with testresults or null on error
      */
-    public static function sendsubmissiontobackend($assignment, $file): ?string {
+    public static function sendsubmissiontobackend($assignment, $submissionid, $file): ?string {
         $backendaddress = self::getbackendbaseurl();
         if (empty($backendaddress)) {
             return true;
         }
 
         // Set endpoint for test upload.
-        $url = $backendaddress . "/v1/task";
+        $url = $backendaddress . "/v1/task/" . $submissionid;
 
         // Prepare params.
         $params = [
diff --git a/dta/locallib.php b/dta/locallib.php
index 844d00697a419936162269a69319bd165655651d..cff2b4e98d786fb48d150c6aea543304ecf32625 100644
--- a/dta/locallib.php
+++ b/dta/locallib.php
@@ -285,7 +285,7 @@ class assign_submission_dta extends assign_submission_plugin {
         $file = reset($files);
 
         // Send file to backend.
-        $response = DtaBackendUtils::sendsubmissiontobackend($this->assignment, $file);
+        $response = DtaBackendUtils::sendsubmissiontobackend($this->assignment, $submission->id, $file);
 
         // With a null response, return an error.
         if (is_null($response)) {
diff --git a/dta/version.php b/dta/version.php
index 471952b4c114be68ffee93ea5fd3f492e602224e..fd56733d18bfe98d7b7ccbd0993c01eb22b60983 100644
--- a/dta/version.php
+++ b/dta/version.php
@@ -28,4 +28,4 @@ $plugin->version   = 2023123001;
 $plugin->requires  = 2020061525; // Moodle 3.9 LTS. Older unsupported versions from the 3.x branch should also work.
 $plugin->component = 'assignsubmission_dta';
 $plugin->maturity  = MATURITY_STABLE;
-$plugin->release   = "3.0.1";
+$plugin->release   = "3.1.0";