You can use a list find first item block with the key pressed sensing block and a list of all the keys that are able to be pressed. Constructing that list by hand will take a while, but fortunately you can use the unicode as letter block and the numbers from to block to programmatically create a list containing all the alphanumeric characters. The rest will be constructed by hand, but there are only 7 left so that will not take a long time.
(don't put an actual space character like i did, put the word "space")
This solution wasn't actually made by me by the way. Also, this code can also be modified a bit to get a list of all the keys that are pressed during a given time.