Hello,
I’m trying to prototype a certain button and it’s not working well. Could anyone help me?

So for example, if I click 2, the 2 button gets the outline (the one 1 has now) and the 1 button should remove it. (I’m sorry for my English ) and vica versa. Could you please tell me how to do this prototype. The first part (2 getting an outline) was easy, but I don’t knowhow to do the second part (1 removing the outline when I click 2).