Quote: Is it possible to use a transition like dissolve
Good question.
In default Gimp Filters -> Animation -> Blend takes 3 layers (2 + duplicate) and produces a blended transition. You need to pad out either side with the before / after frames.
screenshot: https://i.imgur.com/nnaYzLl.jpg
The gmic-gimp plugin has in the
Again add the before / after frames as a separate operation for ease of use.
If you want something like a dissolve transition then probably not Gimp, maybe ffmpeg command line would do it.