(FOR LINUX; I don't know if it's the same for Windows.)
For those of you who might be struggling to manually import this game into itch, simply make your own receipt.json file with the following steps.
1. Make a blank json file and put the following in it:
{
"game": {
"id": 2890613
},
"upload": {
"id": 13209536
}
}
2. gzip the file. (make sure the file ends up with the name "receipt.json.gz")
3. Put an empty folder for the game in the "~/.config/itch/apps" file path. (name it something like 'anomalous-coffee-machine' or 'ACM')
4. Move the game file/executable(in this case) into the new folder.
5. Make sure to give the game file/executable(in this case) permission to run.
6. Create a folder labeled ".itch" in the new folder.
7. Move the "receipt.json.gz" file into the ".itch" folder
8. Tell the Itch app to search for new installs in the manage install locations tab on the itch app.
And voila! The game is now listed. You will likely still need to re-download the game and update the upload ID in the receipt manually, each time you wish to update the game.
I may re-post the steps with an updated upload ID for some of the future updates. (depends on if I see the update and feel like updating it)