The alerts are not displayed in OBS Studio

Check the order of the sources in the scene. The alert widget may simply be hidden by another source. The higher the source is in the list, the higher its priority.
You should also note that the widget won't display anything until an alert appears.

The fundraising widget is not displayed

The most likely cause is that you simply didn't create a goal. After entering the goal data, click "Create goal".
You should also check the order of the sources in the scene. The fundraising widget may simply be hidden by another source. The higher the source is in the list, the higher its priority.