How to set button size on blueprint?

I’m creating a level selection for my game. For that, I’m creating buttons dynamically. This is how my button Widget looks:

And here is part of the code where I create the button. I show the part where I’m setting the button style (working for background) and where I try to set the button size:

But the size seems to be ignored… Any idea on how can I set the button size dynamically?

I know this topic is old, but if someone search for soluthion here I am.

You have to make your button variable and use node “Set Render Scale”.