Is there any free testing send OTP by any way like whatsapp, Email or sms or any other free way?

[TIMAI2]

Follow the guide, it tells you what to do.

If unsure about Apps Script:

Everything you wanted to know about Google Apps Script, but were afraid to ask

Well, not quite "everything", but enough to help create a script, deploy it, update it and approve permissions for it, to begin with. Of course, there is the official documentation: Google Apps Script First two guides to deploy a google apps script, standalone and one that is bound to a spreadsheet: Second a guide to update your google apps script to a new version after editing the script: Third a guide to correctly reviewing permissions for a script (this is also covered in the second …