Layout style in popups

Hello everyone! I have a simple question, I hope you can help me.
While I am developing the content of the screens with "Al Companion", the style appears different in pop-up windows unlike once I install the APK.
I bring you this example, in "Al Companion" I see the edges as round, and once I install the APK I see them as square.
Is there a way to make them rounded like in "Al Companion"? The truth is that I prefer it that way.
From already thank you very much!

Al Companion: