I got this key from Humble Bundle in May 2019.
The game is called "I´m not a monster" on Humble Bundle, but Steam only has a game called "I am not a Monster: First Contact" available.
However, the logo is the same. Also, it hasn't happened for the first time that Humble Bundle called its games slightly different than Steam does.

Please drop a comment if there are any issues with the won key. Thank you and good luck to everyone!