How do I lock rows after data input on excel online

Question

Hi,

I have a spreadsheet which is used by lots of different people at the same time. I want to be able to run office script on excel online which will enable me to lock the rows automatically after someone inputs data in the row so for example:

someone is required to fill out a request for my team to carry out - once we fill in column "AF" with either a Y or N I want all the cells prior to that column to be automatically locked so that the requested than cannot go back and change their request. I would also like the option to unlock this using a password should we need to.

I know i can do this in the Excel App using VBA coding but since this does not work for Excel online I'm really hoping that the Office Script will have the option to do this