Do I Install MacOS on Update disk or on Macintosh HD - Data disk?

Hello! I wanted to reset my Macbook Pro 2017 to factory settings, so I erased the Macintosh HD - Data partition. I restarted and now I dont have an operating system (I also did notice when erasing the HD - Data partition it unmounted from the internal disks tab). I am now booted in disk utilities and I clicked on reinstall macOS. It is now asking me on which disk I should download the OS - on disk Update (which didnt exist before) or on HD - Data (for some reason Macintosh HD doesnt exist anymore even though I didnt delete it). Which one do I choose or what do I do next?