Well, i also realised i was wrong in multiple aspects, here you go, more detailed guide:
1) Prepare a setup, Install SPT on PC1 (That means install EFT with AKI on it)
2) Install AKI on PC2, you don't need game files for that.
3) On PC2 - Change IP and Port, IP is your internal one, you can check it via Win-x > System>Network>Adapter>Settings>Status, something like that, i have a different default language so i can't tell you exact names.
And any port, there is no firewall really in LAN, just don't go above limits, take a simple one, like 3456 or 7777, you may leave it as it is
4) Launch server in PC2, take generated certs from PC2 and put it in PC1 into user/certs, or maybe any folder you'll use next step on. (that's where i was wrong on previous post)
5) Use certutil as guided above
6) Run Launcher on PC1, get in settings, set up your URL, launch the game.
If it's that perfect it'll work, maybe it's not, it's all my assumptions, i don't have 2nd pc as of now to try, sorry.
Maybe someone will give you more detailed instructions on back-end side.