Alignment is necessary, and equally complicated
The instructions make it clear that alignment of the two images you are morphing is absolutely key to getting good results. Seems obvious enough. Popims Animator claims, "The best method consists in using our automatic procedure which is very clever."
I'm afraid not. Launching the automatic alignment tool brings up the window shown above. The first drop-down box represents "Maximum scaling up or down in percent". The second drop-down box represents "Maximum movement in pixels".
So you have the option to shift, resize and crop your images. This is done to both images at the same time and in no way enables you to align anything! Even if you have a great eye and are a savant at estimating distances and relative sizes, there is no way to make sure the images are actually lined up the same.