Protect a Google Sheet

To protect a sheet:

1. Open the spreadsheet.
2. Click the sheet's tab at the bottom of your spreadsheet and select Protect sheet.
3. Optionally, enter a description for the protected sheet in the text box.
4. Change users’ viewing, commenting, and editing permissions by clickingSet permissions.
5. Click Done when finished making changes to permissions.
6. Click Done to protect your sheet.

Who can create protected sheets

Any owner or editor of a spreadsheet can set editing permissions for individual sheets, although editors can’t remove editing permission for owners. Others will still be able to view the data on the protected sheet, but depending on the permission you set for each sheet, they won't be able to make any changes or delete a protected sheet.

Edit a copy of the data from a protected sheet

If an editor duplicates the protected sheet, copies the workbook, or uploads a new version, sheet protection will be disabled. Also, if a viewer creates a copy of the spreadsheet, the data on the protected sheet can be edited in the copy.

Reference: Google Help Protect a range or sheet from being edited