Add in alert for when user isn't found

templates/ccpo/confirm_user.html

@@ -4,6 +4,7 @@
 {% from "components/text_input.html" import TextInput %}
 
 {% block content %}
+  {% if new_user %}
     {% set ccpo_user_form = "add-ccpo-user-form" %}
 
     {% call Alert('Confirm new CCPO user') %}
@@ -32,4 +33,16 @@
         </div>
       </form>
     {% endcall %}
+  {% else %}
+    {% call Alert('User not found') %}
+      <div>
+        To add someone as a CCPO user, they must already have an ATAT account.
+        <div class='action-group'>
+          <a class='action-group__action icon-link icon-link--default' href="{{ url_for('atst.ccpo_users') }}">
+            Return to list of CCPO users
+          </a>
+        </div>
+      </div>
+    {% endcall %}
+  {% endif %}
 {% endblock %}