I tried use save with password and open as read only but when I save the document using “save as” other title, I can modify the content, how to I disable the “save as” feature ?
Can you please describe why would you like to disable changing and saving? Because we don’t know why we can’t provide a good alternative. Maybe you can save a file in PDF like File | Export to PDF.
You can’t at the moment, at least not unless you have control over the computer the file will be used on.[1] Bug fdo#59926 describes how File > Save As… can be used to bypass password protection. There is a Save with password option on the Save dialog that is unchecked by default.
[1] In this instance you may want to consider disabling the Save As… menu item using the method indicated in this thread.