Are you running version 83 or later? I think they introduced the flag in that one. Another solution for Windows and macOS users (no Linux sadly) is to use Edge

Are you running version 83 or later? I think they introduced the flag in that one. Another solution for Windows and macOS users (no Linux sadly) is to use Edge Chromium, which does it by default, and you prefer to donate your data to Microsoft rather than Google like me :)