If you have a worksheet wherein only one person should modify it at a time, you can check the Workbook out, preventing any other user from modifying the Workbook while you have it checked out.
How to check out a workbook
1. Start by clicking 'File' in the upper left-hand corner of your spreadsheet
2. Then click 'Info'
3. Then click 'Manage Workbook' and then 'Check Out'
How to see if a workbook is checked out
To view if a Excel Workbook is checked out, you can see a little icon in Teams or a lock on the file itself in File Explorer:
Alternatively, if you open the file in Teams or Excel online, it will show the document as locked when trying to make it allowed for edits.
If opening the Excel application, you will see it open in Read-Only.