how to install macos ventura in macos catalina ?

If it isn't supported (i.e., if it isn't a 2018 or later model) you can't upgrade to Ventura. You may be able to upgrade to an earlier macOS depending on the model year of your MacBook Air.

The model year of a MacBook Air is available at Apple menu > About This Mac.

A mid 2012 MacBook Air can be upgraded to Catalina 10.15.7 but no later. See: How to download macOS - Apple Support

A mid 2013 and early 2014 MacBook Air can be upgraded to the latest version of Big Sur macOS 11 but no later. See: How to download macOS - Apple Support

An early 2015 and a 2017 MacBook Air can be upgraded to the latest version of Monterey macOS 12. See: How to download macOS - Apple Support

A 2018 or later MacBook Air can be upgraded to the current version of Ventura macOS 13. See: How to upgrade to macOS Ventura - Apple Support

For a MacBook Air, macOS Ventura requires a 2018 model or newer. According to the version info you listed on the question you posted, if you're on macOS 10.15 and your model is a 2012, then macOS Catalina 10.5.7 is the last version supported on your device. If your model is a 2013 or 2014, you can run macOS Big Sur; if your model is a 2015 or 2017 model, you can run macOS Monterey. If you are able to upgrade to macOS Monterey, I recommend doing that, as macOS Catalina is no longer supported as of November 2022. Security Updates and Software Support for macOS Monterey will end in the Fall of 2024.