How to fix print string

Hi Guys, I have a problem. I followed the guide on yt:
Widget Communication In Unreal Engine 5.1 - Part 1 + Using UMG To Modify An Actor. (youtube.com)
UMG to edit actor. my project on AR template. I followed the guide. but I put the logic inside the “BP_Placeable” for first test, I wanted to make a string print on the tap on the button. but it doesn’t work I also tried on “BP_ARPawn” but it doesn’t work. how can I solve? thank you very much