Testing 4th deployment (earlier online file at https://www.geogebra.org/m/meyehupy appear cannot be deployed because it was not public.
There was also peculiar problem of Geogebra Classic Desktop not updating JS script in ggb file. After repeatedly trying to remove previous error due to "if (confirm("Confirm to submit?\nClass: " + className + ", class index num: " + classNum)) ", the script reappeared despite file being saved several times.
And even after file is saved, when uploaded, the online file was not updated and the old "confirm" script remained.
Solution ? Deleted the online applet, renamed the ggb as another file and upload as if a new applet (at the same address). This finally solved the problem.
This is the 6th deployment using https://www.geogebra.org/m/xa2sam3v
Results are sent to google sheet at https://docs.google.com/spreadsheets/d/1-kzHCAdrf_LymIZ3opsx3CI9_Jaj7iNNxJYGr_1MTdk/edit?usp=sharing
This spreadsheet's web app url is currently : https://script.google.com/macros/s/AKfycbxhmT2jRZbP8aBdNqo6e_eGr3fIqN5NgNPEUGHZDhl6hQRte6cN6Nm7xnk6xv976-rYFQ/exec