not 100% sure what you meant by this but,
FREE TUTORIAL FOR SETTING THE GAME'S ICON! (no idea if this is even necessary on mac this is purely windows. it might not properly match up with some computers ui's so sorry in advance i am just a guy on the internet. i'm running windows 11 so you might need to take different steps than me. sorry for that i am a windows 7 girlie through and through my laptop is just new. exceedingly thorough for no good reason but the autism)
1. Make sure that you have a shortcut to the game, since that's what we're setting the icon of! (read substeps to make a shortcut)
1a. Go to your file explorer and select downloads
1b. Open the folder named 'Dead Plate (19)' (make sure you select the unzipped one!)
1c. Right click on the file named 'Game' (NOT 'Game.exe')
1d. Select 'Create Shortcut' (if you can't see this initially select 'Show More Options' first!)
1e. Move the shortcut to your desktop (hold left-click on it and move it to the desktop section)
1f. To change the shortcut's name go to your desktop (see step six) or select the desktop section in your file explorer; find the shortcut, right-click it, select 'Rename', and input the name you want for it followed by the enter key; if you followed step six you might be able to double-click on the name to change it, and if you're in file explorer it might be bound to F2 (make sure you've clicked on the shortcut before pressing F2)
2. Find a website that will convert .png to .ico files (i used this because it was the first option i found)
3. Set the size to 128 x 128 pixels, since this is the original file's size
4. Choose your file
4a. When it opens your file explorer select downloads
4b. Open the folder named 'Dead Plate (19)' (make sure you select the unzipped one!)
4c. Open the folder named 'www'
4d. Open the folder named 'icon'
4e. Select the icon, it should be the only file in the folder
5. Download the converted file
5a. You don't need to put this with the game files in order to set it as the games icon!
6. Go to your desktop (minimize windows so it's visible)
7. Right-click on the shortcut
8. Select 'Properties'
9. There should be an option that says 'Change Icon', choose this
10. Click on the file directory at the top of the icon selection and set it to wherever you stored the .ico file
11. Select the correct file from the list (if there is one)