Or, if you already have an active Safari window, click ‘File’ in the macOS menu bar, then select the ‘New Window’ submenu to open one of your profiles. Or you can memorize the keyboard shortcuts that ...

2. Select "Safari" and then "Preferences." 3. Toggle over to the "Advanced" tab and tick the box next to "Show Develop menu in menu bar" - you should see "Develop" appear in the top toolbar.