How can I save tabs in iTerm 2 so they restore the next time the app is run?
You can Save and Restore Window Arrangement with ⇧ ⌘ S and ⇧ ⌘ R options under the Window screen in iTerm2
You can start the default Arrangement Option to enable are at Preferences -> General -> Startup -> Open default window arrangement .
You can add arrangements with the ⇧ ⌘ S and manage them under Preferences -> Arrangements tab .
In iTerm go to Preferences -> General and under Startup set Use System Window Restoration Setting.
Go to macOS System Preferences -> General and make sure that Close windows when quitting an app is unchecked.