Hi @Elena,
I’m afraid I bring you bad news. Processing Python mode is no longer maintained, Jonathan resigned a few years ago. And Python Mode is not working properly on Processing 4.
You can still run your sketches on Processing 3.5.4 + Python Mode for Processing 3, but I’ve heard reports that “Export application” was broken already. YMMV
I used to ship a huge zip file with the Processing IDE and my sketches for a while.
And I’m using py5 for new projects (and shipping huge zip files with portable Thonny IDE because usually I’m unable to make pyinstaller work).