Cannot Install MacOS Catalina in Recovery Mode
Tony looks to have the scoop here on an installer selection error for about 24 hours yesterday. Try again exactly what you did previously after 0000 UTC Thursday 6 August.

When you power it off, I would attempt a second time to do an erase install.

Hold Option-Command-R at start.
Use Disk Utility when you are to the “install” screen - delete all the volumes - especially if you have more than one that says “Data”
Then Erase the entire drive - leave Untitled as the title.
Then install macOS

If that doesn’t work, you may have a hardware issue and need to contact support.

https://support.apple.com/en-us/HT208496
https://eclecticlight.co/2020/08/03/how-should-you-clean-re-install-catalina/

Or perhaps try the App Store - step 2 in this other answer.