Your the browser stores a lot of information that is interesting for an attacker: social networks, mail, bank and more. Therefore, it is better to protect the browser using third-party methods, because the standard ones cannot set a password.
The PassBrow extension for desktop browsers will help with this. Each time you log in, you will be asked for a password. The extension is available on browsers: Chrome, Edge, Firefox, Brave. After installing the plugin, a tab with settings will open. Set a password and the extension will start working.
Android has an easier way. If your smartphone does not support the application lock function, then install the application AppLock.
Give the application the necessary permissions. Click on a browser in the list and select a blocking method. Done, now when you log in, the browser will ask you to log in with the selected blocking method.