Since you do not know the platform, Itch is not one of these Steam key shops. You bought the games on Itch and practically all of them do not have drm. Some games however do offer a drm version on another platform, like Steam, and would give you that version as a bonus.
Only games in this list https://itch.io/games/steam-key offer a Steam key. It will say so under the buy button of a game.
In order to download this game you must purchase it at or above the minimum price of $5 USD. Your purchase comes with a Steam key. You will get access to the following files:
Bundles and Megabundles can be different.
The game you mentioned does not offer Steam keys for this mega bundle.
In order to download this game you must purchase it at or above the minimum price of $7.99 USD. Your purchase comes with a Steam key. (Note: Steam key not included in No ICE in Minnesota) You will get access to the following files: