There is no installation images but it is fairly easy to install a server system.
Go to Releases 路 manjaro-architect/download 路 GitHub and download the latest ISO.
Prepare a usb stick using ventoy and copy the ISO onto it.
Plug it and start the system.
login and run setup.
You use dialog to customize the install using a simple menu.
Then I must be quite stupid make no sense 
I use Manjaro on a PI4 (packed in box with a 512G m2 ssd) - it runs quite well - using nginx as webserver - and a couple of domains, an unofficial repo on [https://manjaro.dk], my notepad [https://root.nix.dk], using LetsEncrypt for certificates, a couple of archives [linux-aarhus archive @ uex.dk] - some custom ISO [linux-aarhus archive @ uex.dk]