Get list of keys from action mappin

There’s a topic about it from almost 3 years ago and it seems to not have got a updated answer about it, so i decided to create this topic :
I’m trying to create a action bar with UMG , and the best way to do it i would need something like this : get all keys from the input action , then make array out of it; make it a blueprint function(no problem with it being written in c++, but has to become a blueprint function).
How can i do it?