How to prevent adding values if several users trying add values at the same time to the same row?

[nodirhajiev]

I've tried adding value to the table from 2 accounts at the same time on AppSheet, only the last user action accepts. 
How to make warn or prevent to user if he adds value to the same row which is added by other user?

[TeeSee1]

Unless there has been any fundamental change in AppSheet structure..

https://www.googlecloudcommunity.com/gc/AppSheet-Q-A/Prevent-or-warn-when-different-users-are-editin...