Provided text for a button tooltip

locale/en_US/messages.php

@@ -87,7 +87,9 @@ return [
             'DENY'                      => 'Deny organisation registration',
         ],
         'JOIN_REQUEST' => [
-            'SUBMIT_SUCCESSFUL'        => 'Request to join organisation <strong>{{name}}</strong> sent',
+            'SUBMIT_SUCCESSFUL'         => 'Request to join organisation <strong>{{name}}</strong> sent',
+
+            'REQUEST'                   => 'Request to join organisation',
 
             'CANCEL'                    => 'Cancel request to join organisation',
             'CANCEL_CONFIRM'            => 'Are you sure you want to cancel your request to join the organisation <strong>{{name}}</strong>?',