How can I find the codes for all of the artifacts in risk of rain 2? I have command but that's all.
You need to find a key, use it to unlock a challenge and then complete it:
To unlock Artifacts you need to use the correct Artifact Code in Sky Meadow, using the Compound Generator below the map, then interacting with the laptop. A Portal to the trial for that Artifact in Bulwark's Ambry will spawn.
The Compound Generator will cycle in the order: square, circle, triangle, diamond (■ ● ▲ ♦)
In Bulwark's Ambry, the Artifact whose trial is being attempted will be active and an Artifact Key will be on an elevated block in front of the Artifact Reliquary. The player must give the Artifact Key to the Artifact Reliquary, which will cause monsters to start spawning, with more Artifact Keys dropping from randomly killed monsters. Using an Artifact Key will remove them from all player inventories.
Upon destroying the Artifact Reliquary, the Artifact can be taken and a portal to a First Stage will appear.
You should search for codes on tablets like this one:
All artifact codes are under this spoiler: