You can make your own cert. To make sure your cert belongs to you (your site) it is signed by authority and the client then may verify that authority (which cetificate is preinstalled in their system) in fact had verified ownership of your site and then signed your cert claims with their private key.
Right now I’m enjoying Witchfire. Although it’s not just FPS, the FPS part is good, along with the atmosphere of medieval-inquisition times and a powerful witch yet to be faced.
Gameplay consists of sessions on several islands where you kill enemies, clear up events and gradually unlock new game parts. On successful extraction you bring back witchfire (the same thing as souls in Dark Souls) to spend on increasing of one of six characteristics.
There are a bunch of weapons unlocked through research and each upgradable up to 3 tiers, by completing requirement tied to each gun.
It is fun and keeps me engaged for several days already. But if you’re not into repeating runs and rather play story based FPS, or don’t really like the theme, maybe it’s better to pick something else.