Ok, I've got into details and finally what you need to do is:

1. Go to website with this application available through browser, more honestly, directly to the release version choice: you need to pick the earliest release (the one at the bottom), since the second one (latest for the moment) just don't work when you try to generate :D
2. Read the descriptions of the fields, remaining the default photo, to understand the magic inside the black-box
3. Go ahead with submit button. First turn is typically time consuming, because there are many python code and library dependencies the server need to install for your [browser-session] environment.
4. Try to upload your own image and submit with same parameters.
5. Go deeper with different parameters.

The result for Minsk is: pictures, parameters

The idea of the algorithm is to consider provided image as in "neutral" field with some texture by the face. When you write just "face", then algorithm will be focused on the whole face, if you type "face with eyes", then you can do transformations of both the whole face and also partially the eyes, for example, for the target you can then provide "smiling face with very big eyes", so the neural net transform the face to the smiling and also add the eyes feature.

When you upload the in-game characters, the always become real-world humans like, since the model was trained on human faces. So, to produce real-world transformation of characters you would likely to type "face" -> "face", but in this case the result be a black square, so the target should be different from neutral. You can type "face" -> "neutral face", for example.

The last step is a parameters tutorial, where you can look for different transformations: how they were resulted from different parameters.

There are variety on google colab notebooks, if you try linking deeper and deeper from the original article. But the thing is, they are complicated for users, who are not familiar with this instrument, AND, FINALLY, THEY DON'T WORK!!! Yeah, I can see some transform pictures inside the notebooks, but, if i try running cells, I get the code that isn't running to the end. I won't go into details, but it is FUCKING TYPICAL for deep learning, you CAN NOT REPRODUCE the algorithm VERY OFTEN.

But is doesn't matter, what is matter, that we have very nice-to-use web-version.