How works the function in sheet web vs sheet app?

Question

I did a script in sheets and i linked an image (to looks like a button) and everything is fine WHILE USE SHEET WEB if you use SHEETS APP my "button" its just an image, my question is why in sheets web is working well and sheets app is not??

function Boton () 
{
   var ui = SpreadsheetApp.getUi();
   ui.alert('Tu reporte fue enviado');

}