title: Autolock Google Sheets cells after the first entry
body: <p>I'm trying to use Google Sheets as a sales register for my business. However, there is a specific detail I'd like to configure about the input of information, but couldn't sort it out yet.</p>
  
  <p>I created a table where you enter all the information (such as the date, item sold, total amount, etc.). Everything works perfectly with the table. However, I would like it to automatically prevent any changes to the information in any cell, right after said information has been entered. Let's say someone puts a quantity, then chooses another cell and tries to change the quantity again, but can't due to the protection.</p>
  
  <p>I found some information about autolock at a certain time here: <a href="https://stackoverflow.com/questions/31625064/locking-cells-in-google-sheets-at-a-specific-time">Locking cells in Google Sheets at a specific time</a> but that's not what I need. Also, I'm a beginner and I think some things have changed in Google Sheets because I couldn't make it work, even with the lock by time. I would really appreciate any help you can offer.</p>