How to enable kernel core dumps on catalina

I am trying to set up catalina machine to point to a kernel core dump server. However, I get the following (when booted to the recovery partition):

$ nvram boot-args="debug=0xd44 _panicd_ip=<CORE_SERVER_IP>"
nvram: Error setting variable - 'boot-args': (iokit/common) general error

I am booted into the recovery partition. Any ideas on how I can point my machine to the kernel core dump server?