ASSUMING you went online and read their official docs and FAQ…
They are heavily pushing Docker, and the last I checked, it was the most up-to-date guide. For what it’s worth, the manual install is much easier, and I say that having 5 servers and 30 apps in my homelab.
Keycloack was easier than Frappe docker for me, and for those of you who don’t know, that is saying something. Docker is to scale, but it takes effort.
So, go with their docker or manual install. For the manual install, checkout this script. It’s awesome. @flexy2ky is a legend. Send him $$$ if you think about it as he saves you HOURS of work. GitHub - flexcomng/erpnext_quick_install: Unattended install script for ERPNext Versions, 13, 14 and 15
Other resources off the top of my head: