The stabilize filter is a clip-only filter. This means that you have to put your video onto a track and select it. Then the filter will appear in the filters list.
It is not necessary to use the Timeline or add it to a track to stabilize a clip. You can do it in Source player as well and then just export from Source.
Thanks for the clarification. So ‘clip-only’ means that it cannot be applied to a track and so will not be displayed if the track is selected. Is that correct?