Try to add validation

second.py

@@ -102,6 +102,12 @@ def install(app_name):
 @app.route("/deploy/<app_name>", methods=["POST"])
 def deploy(app_name):
     """Deployment end-point for an app."""
+    if app_name == "gitea":
+        form = GiteaInstallForm(request.form)
+
+    if not form.validate():
+        return render_template("install.html", app_name=app_name, form=form)
+
     environment = get_loaded_env(app_name, request.form)
 
     # Note(decentral1se): how to handle the following?