Can't install kext, "Read-only file system"

So, I've been racking my brain against the wall for the last 6 hours trying to get this to work and I'm still at a loss..

I'm trying to install a kext on Big Sur from this repo, https://github.com/SimulPiscator/vpcm, and when I try and move the compiled kext to /System/Library/Extensions I keep getting 'Read-only file system' error..

• I have disabled SIP
• Tried enabling root user
• Added myself to the 'wheel' group
• Reduced security level in security utility
• Tried changing permissions on the /System dir, keeps telling me I don't have permission.

I feel like I'm missing something obvious... Every article I've seen online tells me to put the kext in that directory and run kextload.. But how the heck do I get write permissions to that directory??

So, I'm not sure if this is what is supposed to happen or not, but placing the kext in /Library/Extensions instead of /System/Library/Extensions worked.

I'm not sure if this is the correct thing to do but since it works, I'm not complaining.