I want to display some data while the script is running by inserting some 'alert' to pop up during process. For example i'm modifying a google sheet, reset range of cells, unmerge and merge, set Validation etc. and i put some alert on any specific task to monitor.
I don't want to use getUi().alert() because i don't want to interact with the dialog box. I need non modal dialog without user interaction. I want the script to keep running and keep show some pop up until the script is done. I can use Logger but i just want to experience in realtime what the script doing right now and which part that makes process so slow etc.
toast(msg) should be what you are looking for.