I entered a password to protect a spreadsheet from opeining and it still opened without requesting password. Help

I wanted to prevent a spreadsheet from opening without entering a password. I followed the instructions and it still opened without requiring a password! What did I do wrong?

I followed the instructions and it still opened without requiring a password! What did I do wrong?

it’s tough to answer this. You never mentioned which instructions you followed; and how did you follow those (exact steps) - so you didn’t tell what did you do at all - then how can someone tell what did you do wrong?

Among all other things, don’t forget to mention which format (ODS? XLS(X)? XML? CSV?) did you use for saving.

Please edit the question to add the information.