lost administrator

I am not able to update the MacOs Ventura as I am told that I am not the owner and none of my passwords work.

I think I tried all the tips on the community unsuccessfully.

There are two profiles created but none of them can update the system app.

I tried to boot on a flash USB-key but I cannot donwload the MacOs Ventury app as I am not the owner and I cannot remove the first user consider as owner and I have no clue on how to set the mac to factory settings.

Do you know where I can find a valid macOs installVentura.app to create a bootable flash key and reinstall from scratched macOs?

Thanks for your help