Fix template name

core/templates/play/initialize_participant.html

@@ -0,0 +1,11 @@
+{% extends 'base.html' %}
+
+{% block content %}
+<h1>User for a Game:</h1>
+<div class="input-group  border-blue-600 border-2 rounded-xl shadow-md">
+    <form method="post">
+        {% csrf_token %}
+        <button type="submit">Speichern</button>
+    </form>
+</div>
+{% endblock %}