don't allow user to edit cells after entering data only for once except sheet owner

[sanjeev kumar]

hi 

    in sheet "FMS" i am trying to apply a script from chat-gpt for column AA:AB. there are prefilled data before applying the script. that is working the wrong way. the user to whom i have shared the file is allowed to change the prefilled data in column AA while in column AB is it is not allowing to fill even empty cells.

what i want is prefilled data should also be protected and the non empty cells should allow to enter data only once. no one can change the data except the file owner. i am not familiar with the scripts. i have pasted the script in line 487. please modify that accordingly.

https://docs.google.com/spreadsheets/d/1ujyQwVeuRF64m7ojnafG_cs-wXANWdlwhGWSWpCyEeg/edit?gid=663292535#gid=663292535

[Ed Robinson]

Hi Sanjeev,

Your requirement to locking cells in a sheet after editing is a very common request. This is possible. 

I wrote a sample that shows how to do it, available on GitHub.

To use the technique, you'll need to be familiar with Google Apps Script. chat-gpt is a wonderful tool, but has limits

Ed

[sanjeev kumar]

i have seen the code but don't know how to change according to my need. i don't know anything about apps script.