can't reboot my usb with catalina or mojave

i have mackbook air 2014, i have install the new 10.9.5, but this version have missing many things like photos app or many things other problem, i want to down grade my software and try for macOS Catalina 10.15 and then try with macOS Mojave 10.14, but show me this message always.

*To use this tool, you must download the macOS installer application on a Mac with 10.12.5 or later, or El Capitan 10.11.6. For more information, please see the following: https://support.apple.com/kb/HT201372.*

but these software not availabe on apple support website, guide me plz