I purchased this and OACM today and neither have a button for a steam key. Followed the instructions given for the user below. Let me know if you're able to help!
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Sorry you are having this issue. There is no need to worry, you will have a Steam key for both with your purchase. As to why you don't have the option to get your key, I am not sure why. It would probably be best to contact Itch support as they are the ones that would be able to help you with this issue. I have just checked too and everything is setup correctly on my end. When you do get it sorted out with Itch, if you could post back how to fix this issue that would be great! :)
Sorry again that you are having this issue!
So I got through to Leafo (runs Itch) and it sounds like you will still need to get in contact with their support. I am not sure why their support has been so slow but they do seem to respond a lot quicker on Discord. Here is an invite to the Itch Discord server: https://discord.gg/RWgYGnrQZt
If you ping one of the admins and give them your ticket number they can usually fast track the whole process for you.
Sorry this whole process has been such a pain, I am really not sure why you are having these issues.