They are part of the installation. None of them are independently downloadable.
Either something is wrong with the installation file that you downloaded, or perhaps there were either permissions problems or an antivirus running (which blocked installation of those components). Given that you're on MacOS, neither of those seems likely (unless you elected to install somewhere other than your system Applications folder). Lots of us are on Macs and nobody has reported this issue here...
What country specific version are you trying to install? Did you try re-installing?
PS. Your signature says MacOS 11.4 ... if you haven't already, update to 11.5.2, although I don't see that as making a different in the installation issue you're experiencing.
One of the forum moderators
AC 28 USA and earlier • macOS Sequoia 15.2, MacBook Pro M2 Max 12CPU/30GPU cores, 32GB